The latest on the Ukraine-Russia crisis

The EU urged Russia to de-escalate by substantially withdrawing military forces from near its border with Ukraine and highlighted the “increase in ceasefire violations” along the line of contact in eastern Ukraine in recent days.

“The EU condemns the use of heavy weaponry and indiscriminate shelling of civilian areas, which constitute a clear violation of the Minsk agreements and international humanitarian law,” read the statement from the EU’s high representative on Saturday.

The EU statement went on to commend Ukraine’s “posture of restraint in the face of continued provocations and efforts at destabilization" and expressed concern at “staged events” that it said could be used as a “pretext for a possible military escalation.”

This statement comes after Ukrainian officials raised concerns about expected “provocations” in breakaway regions in eastern Ukraine, saying they expect Russia to be involved in false-flag operations there.

On Friday, Oleksiy Danilov, secretary of Ukraine's National Security and Defense Council, said the self-declared republics of Donetsk (DPR) and Luhansk (LPR) had alleged Ukrainian forces would launch an offensive against them – something Danilov called “completely untrue."

Danilov was speaking soon after an explosion in Donetsk wrecked a vehicle close to the headquarters of the Donetsk People's Republic. The cause of the blast was unclear.

"There is a great danger that the representatives of the Russian Federation who are there will provoke certain things. They can do things that have nothing to do with our military," he said.

"We can't say what exactly they are going to do, whether to blow up buses with people who are planned to be evacuated to the Rostov region, or to blow up houses, we don't know," he said, without providing any evidence of such plans.

Also on Friday, the foreign ministers of Germany and France said they do not see “any grounds” for DPR’s allegation, warning that “staged incidents could be misused as a pretext for possible military escalation."

The EU also said it was witnessing intensified “information manipulation efforts” and expressed support for the Organization for Security and Co-operation in Europe's Special Monitoring Mission, calling for the mission to be allowed to carry out its mandate without any restrictions.

“The EU sees no grounds for allegations coming from the non-governmental controlled areas of the Donetsk and Luhansk regions of a possible Ukrainian attack," it said. "The EU urges Russia to engage in meaningful dialogue, diplomacy, show restraint and de-escalate.”

The separatist-controlled areas in Ukraine's Donbas region are known as the Luhansk People's Republic and the Donetsk People's Republic. The Ukrainian government in Kyiv asserts the two regions are, in effect, Russian-occupied.

The self-declared republics are not recognized by any government, including Russia. The Ukrainian government refuses to talk directly with either separatist republic.  

President Joe Biden is being briefed "regularly" on the situation in Ukraine by his national security team at the White House this weekend, press secretary Jen Psaki said in a statement.

On Saturday afternoon, Biden received an update on Vice President Kamala Harris' meetings at the Munich Security Conference. On Sunday, Biden will convene his National Security Council to discuss developments in Ukraine, Psaki said. 

"President Biden continues to monitor the evolving situation in Ukraine, and is being updated regularly about events on the ground by his national security team. They reaffirmed that Russia could launch an attack against Ukraine at any time," Psaki said in the written statement. 

Ukraine President Volodymyr Zelensky said he had an “urgent” conversation with French President Emmanuel Macron in which he discussed the “need and possible ways of immediate de-escalation," as the US and allies insist Russia is moving to conduct an attack on Ukraine.

A group of journalists, including from the French agency AFP and CNN, came under mortar fire Saturday when accompanying Ukraine's interior minister on the frontlines.

The call between Zelensky and Macron comes ahead of an expected conversation Sunday between Macron and Russian President Vladimir Putin.

Putin and Macron will speak by phone on Sunday, Russia's state-run news agency RIA Novosti said Saturday, citing the Kremlin pool.

“Macron has become Putin's most frequent person to have conversation with in recent days (in recent times). The leaders of Russia and France will talk by phone over the weekend," Ria Novosti said in a tweet.

A CNN team and other journalists accompanying Ukraine’s interior minister on a tour of the front lines in eastern Ukraine came under mortar fire Saturday.

No one was injured.

Interior Minister Denys Monastyrskiy sought cover as several mortar rounds landed nearby. Shortly after the shelling, he gave interviews to international media in Novoluhanske. 

About a dozen mortar rounds landed within a few hundred meters of the group.

He said that it had been his first time under fire. He told reporters that he was in the car en route and they had to stop every time they heard shelling and lay on the ground.

At a news conference later in Kramatorsk, Monastyrskiy was asked by CNN what role Ukraine believed that Russian military advisers were playing in the fighting in the eastern part of the country. 

"We have information about the advance of the Russian army along our territory," he said. "There is also information that certain units of the Wagner PMC have entered our territory. The purpose of the stay is to organize sabotage in our territory."

Some background: Wagner is a private Russian paramilitary force that has long been associated with the separatists in eastern Ukraine and has also deployed to Libya, Syria and the Central African Republic, among other countries.

The Russian government denies any connection with Wagner or other private military contractors.

Over the past few days, the Ukrainian armed forces have reported a surge in heavy weapons fire against Ukrainian positions along what is known as the line of contact.  

The Ukrainian Ministry of Defense said that through 17:00 local time (10 a.m. ET) Saturday, "70 violations of the ceasefire regime were recorded by the Russian occupation forces, 60 of which by using weapons prohibited by the Minsk agreements."

The ministry also said that two Ukrainian serviceman were killed and four wounded on Saturday.

The Ukrainian Defense Minister Oleksiy Reznikov repeated in a Facebook post Saturday that Ukraine had no plans to launch an offensive against the breakaway regions, as claimed by the leaders of the self-declared Luhansk and Donetsk republics. 

"We do not plan any offensives, but we will not allow the firing on the positions of our troops and human settlements with impunity," Reznikov said.

British Foreign Secretary Liz Truss accused Russia on Saturday of not being “serious about diplomacy” while warning that the “worst-case scenario could happen as early as next week.”

Truss also said Ukrainian President Volodymyr Zelensky's speech at the conference was “extremely sobering.”

Truss said the United Kingdom would stand in unity with its partners to support Ukraine.

“We need to be strong because that is the only thing that Russia understands. And I think we need to be strong in supporting Ukraine and not selling Ukraine out with concessions on sovereignty,” Truss said.

“Ukraine needs our support at the United Nations and at the OSCE and they also need our economic support because there is a real threat of economic destabilization. They need our defense support, and the UK is committed to continuing to supply that support, standing shoulder to shoulder with Ukraine,” she added.

The foreign secretary stressed that the UK is “resolute in imposing severe costs on Russia in the event of an invasion, including tough sanctions.”

“We will stop oligarchs being able to move their money internationally. We will stop them traveling, and we will make it tougher for Russian companies to tap into our capital markets. And we're also going to make it harder for Russia to access sovereign debt markets,” she said.

Truss said the UK stands with Europe and the United States in being “completely united in support of Ukrainian sovereignty and self-determination.”

“What this crisis has demonstrated is we are united. We are prepared to put tough sanctions in place in the event of an incursion. We are prepared to supply that defensive support to Ukraine,” Truss said.

Mariupol is a city in southeastern Ukraine that literally straddles war and peace. Here, even the local chaplain wears two hats — or robes — military and civilian. 

Roman Peretyatko is the chaplain at the Archangel Michael church in Mariupol, but he is also the military chaplain with the Ukrainian Border Guard Service. For him, this eight-year war between Ukraine and Russian-backed separatists is not only professional but also personal.

At the "Old Crimea" graveyard in Mariupol, a vast cemetery on the outskirts of the city, a plot of graves is dedicated to the fallen soldiers in the war.

Peretyatko showed CNN the grave of a friend who he buried in 2015. Among the other tombstones, veteran Ruslan Vostovoit told us their deaths were needless, but that Russian President Vladimir Putin is responsible because “he wants to play his game."

Back at the church, Peretyatko read the morning prayers where both he and locals are praying and serving peace.

Many locals come to him for solace.

“If they ask what’s going to happen next, we say it’s God’s will. We prepare for the worst and hope for the best," Peretyatko said.

US Defense Secretary Lloyd Austin said he does not believe Russia’s increased military presence along the Ukraine border is a “bluff” and that Russian President Vladimir Putin could decide to attack Ukraine “in short order.”

Austin told ABC News in an interview taped Friday that Russia has developed the combat infrastructure along Ukraine’s border to “conduct a successful invasion.”

When asked about the possibility that Putin is increasing tensions without intending to actually invade, Austin said, “I don’t believe it’s a bluff.”

“I think he’s assembled the right kind...of thing that you need to conduct a successful invasion," he said. “If they were redeploying to garrison, we wouldn't be seeing the kinds of things in terms of not only combat power, but also logistical support, medical support, combat aviation that we've seen in the region."

Ukrainian President Volodymyr Zelensky told CNN that NATO partners need to clarify a timeline upon which Ukraine can join the alliance. 

“Ukraine needs security guarantees,” he told CNN. “We are smart people, we are not narrow-minded. We understand there are lots of different risks because of NATO, there is no consensus around other allies, everyone is saying there is some distance that we need to go between Ukraine and NATO that we need to walk. All we are saying is: Tell us how much time does it take to complete this distance?” 

In earlier remarks to the Munich Security Conference, Zelensky posed the question as to why Ukraine was not being permitted to join NATO.

CNN also asked Zelensky about the use of US intelligence to dissuade Russian President Vladimir Putin from invading Ukraine. 

“I am grateful for the work that both of our intelligence has been doing. But the intelligence I trust is my intelligence. I trust Ukrainian intelligence who ... understand what's going on along our borders who have different intelligence sources and understand different risk based on intercepted data. … This information should be used," the Ukrainian president said.

Zelensky called for international partners to support Ukraine by investing in the country. 

“Strengthen our arms … our economy. Invest in our country. Bring your business in,” he said. “We are not panicking; we want to live our lives."

House Speaker Nancy Pelosi warned on Saturday that the United States will impose sanctions "never seen before in terms of the intensity and timing" if Russia invades Ukraine.

“We’re not for any war," said Pelosi, who is leading a congressional delegation at the Munich Security Conference. “Diplomacy, diplomacy, diplomacy — and that’s why we’re talking about sanctions in the event of an invasion. These are sanctions as if you’ve never seen before in terms of the intensity and timing.”

Asked if sanctions will be enough if Russia invades, Pelosi replied, "I do, because we have not seen sanctions as we’re going to see now." 

Pelosi also postulated as to what could be motivating Russian President Vladimir Putin, suggesting that he could take action to mark the 100th anniversary of the Soviet Union founding.

"I think that part of his fear, Putin’s insecurity, is that the people of Ukraine have embraced democracy, free-market system and the rest. And they like it and they will not choose the Russian system over theirs," she said.

Forty members of Congress, both Democrats and Republicans, are attending the conference in a show of solidarity with NATO as Russian troops amass along the border with Ukraine. 

“In the face of that threat, NATO is more united than ever, ready to impose the most severe sanctions ever. We hope and pray that this will not be necessary,” said Rep. Adam Schiff, chair of the House Intelligence Committee. “The door to diplomacy remains open and will be open until and unless Putin slams it shut.”

“The rest of the world is watching us, and if we don’t act in unison to bring about the toughest sanctions that have ever been deployed, then other nations will feel free to subjugate their democratic neighbors,” Schiff said.

CNN's Lindy Royce-Bartlett contributed reporting to this post.