By Zamira Rahim, Melissa Macaya and Ed Upright, CNN
NATO Secretary General Jens Stoltenberg welcomed US President Joe Biden to Brussels and thanked him for his "rock solid commitment to our Alliance."
"I know we can count on America & America can count on #NATO2030," Stoltenberg tweeted Monday.
The key summit kicked off on Monday with a family photo of the leaders in attendance.
NATO's leaders have gathered in Brussels, Belgium, for a "family photo," a picture taken of the group at each landmark summit.
The photo session will be followed by the day's main agenda, with the global leaders set to discuss Russia and China, among other matters.
The summit is Biden's first alliance summit as US president. It follows his appearance at the G7 summit over the weekend in England.
Many of Biden's fellow leaders at the NATO summit have commented on the US' global role and recommitment to multilateralism under the new president.
Read more about today's meeting here.
Watch the historic moment unfold:
From CNN’s Vasco Cotovio in London
Italian Prime Minister Mario Draghi says Monday’s NATO summit is part of the ongoing process of reaffirmation of the US’s role within the alliance, after four years of “undecided” membership under former President Donald Trump.
“This summit is the continuation of the G7 encounter yesterday,” Draghi told journalists when he arrived at the summit in Brussels.
“It’s part of the reaffirmation and rebuilding process of the fundamental alliance for the United States, which was, how to put it, ‘undecided’ during the previous administration.”
“Think that President Biden’s first visit is to Europe, and try to remember where President Trump’s first visit was to,” Draghi also said.
President Trump’s first trip abroad as US President was to Saudi Arabia.
“So we are here to reaffirm this alliance but also to reaffirm the importance of the European Union within it,” Draghi added.
“A stronger European Union means a stronger NATO," he said.
From CNN's Kevin Liptak in Brussels
US President Joe Biden has arrived for his first in-person North Atlantic Treaty Organization (NATO) summit after taking office, vowing to reaffirm the United States' commitment to a military alliance his predecessor in the White House viewed with disdain.
The summit comes as Biden looks to reassert American leadership on the world stage and strengthen global partnerships during his first international trip as President. It comes on the heels of several meetings with US allies and the annual Group of Seven (G7) summit in Cornwall, England.
Biden said Sunday he would reiterate the US's commitment to NATO's collective defense clause and communicate to allies that it believes Article 5 is a "sacred obligation."
Here's what to expect of today's meetings:
From CNN’s Saskya Vandoorne in Brussels
French President Emmanuel Macron and Turkish President Recep Tayyip Erdogan had a “long” meeting on the sidelines of the NATO summit in Brussels on Monday.
“Ahead of the NATO summit, I had a long one-on-one exchange with President Erdogan,” Macron tweeted on Monday.
“In order to move forward with clarity, respect and exigency.”
According to the French Presidency, the meeting between the two lasted a total of 45 minutes, longer than expected, because the two men were keen to discuss all matters in depth, including strategic clarification among allies on the values, principles and rules within NATO, as well as the situation in Libya and Syria.
Macron also used the opportunity to clarify his and France’s stance on Islam.
“The meeting was an opportunity for the President to reiterate that France respected Islam and Muslims, that French secularism respected all religions,” a spokesperson for the French Presidency said.
“These are the values of the Republic. Macron highlighted that these values should be respected and should not be instrumentalized.”
US President Joe Biden is also set to meet with Erdogan at today's summit.
See the French president's tweet:
From CNN's Betsy Klein in Brussels
US President Joe Biden met with NATO Secretary General Jens Stoltenberg in Brussels after arriving for his first in-person summit of the alliance after taking office.
"I want to make it clear, NATO is critically important for US interests in and of itself. If there weren't one, we would have to invent one. It allows America to conduct its business around the world in a way that never would have occurred were it not for NATO," Biden told reporters, noting the importance of Article Five as a “sacred obligation.”
“I just want all of Europe to know that the United States is there, the United States is there,” Biden said.
The US President cited challenges facing the group of 30 nations, including that Russia is “not acting in a way that is consistent with what we had hoped,” and China, citing agreement at last week’s Group of Seven Summit.
Stoltenberg, echoing other world leaders at the G7 summit, said NATO “will open a new chapter in our transatlantic relationship with the meeting today to discuss a wide range of issues, including Russia.”
He continued, “I think that allied leaders look forward to consulting with you ahead of the meeting with President Putin. We will address China, and we have seen a convergence of views among allies,” outlining China’s “coercive behavior” as something NATO needs to respond to as a group.
Biden also thanked Stoltenberg for his “incredible leadership.”
“Quite frankly, we have competent people coming, but I wish you were not leaving,” he said, praising Stoltenberg’s ability to pull people together.
More on today's summit: The NATO summit comes as Biden looks to reassert American leadership on the world stage and strengthen global partnerships during his first international trip as President. It also comes on the heels of several meetings with US allies and the annual Group of Seven (G7) summit in Cornwall, England.
Biden said Sunday he would reiterate the US's commitment to NATO's collective defense clause and communicate to allies that the US believes Article 5 is a "sacred obligation."
During Monday's summit, NATO leaders are expected to discuss how to manage future threats and "ensure effective burden sharing," according to White House press secretary Jen Psaki.
Read more about today's meeting here.
CNN's Kevin Liptak contributed reporting to this post.
From Nina Avramova in London
NATO Secretary General Jens Stoltenberg has said that China does not “share our values,” citing Bejing's crackdown on democratic protests in Hong Kong and persecution of minorities as a key difference with the alliance.
“We see how they crack down on democratic protests in Hong Kong and also persecute minorities in their own country and use modern technology, social media, facial recognition to monitor and surveillance their own population in a way we've never seen before,” he said ahead of the key summit in Brussels on Monday.
The issue is about what to do “at home,” explained Stoltenberg, because “China is coming closer to us.”
“We see them in cyber space, we see China in Africa, in the Artic but we also see China investing heavily in our own critical infrastructure and trying to control it," the NATO chief added.
"We have seen the discussions about 5G Huawei and that's the reason why the NATO 2030 agenda is so important.”
However, China is not an adversary, or enemy, Stoltenberg stressed.
There are also “opportunities” in NATO’s relationship with China, according to the Secretary General.
“For instance, on arms control and climate change we need to talk to China. At the same time, what we have seen over now several years is a significant military build-up by China,” he said.
From CNN's Sharon Braithwaite in London
Lithuanian President Gitanas Nauseda said Monday that Russia was trying to "swallow" Belarus and that NATO needed to have a "very clear, united and decisive response" to the situation.
Nauseda made the remarks as he was arriving at the NATO summit in Brussels, which will focus on Russia, China and Afghanistan.
"We have a lot different kinds of threats arising in the region," Nauseda said, adding that the country is seeing "additional threats coming from the east, which are related to aggressive behaviour of Russia."
Nauseda said the situation in Belarus was also becoming an issue for the region.
The country has seen repeated unrest since a hotly disputed election last year.
"What is also very important (is) that we see the efforts of Russia to swallow this country," Nauseda said.
"Belarus is losing the last elements of the independence, and those trends are very dangerous and we have to be aware of them," he added.
"I would expect that President Biden will send a very clear message about the decisiveness and unity of NATO, and will react with very clear messages to what is happening," he said.
Nauseda added that NATO could not have closer ties with Moscow until the country changed its "pattern of behavior."
From CNN's Stephanie Halasz
German Chancellor Angela Merkel has listed some talking points for the upcoming NATO summit.
Arriving in Brussels, Merkel noted that the event was the first summit with the new US President.
She then listed some challenges to be discussed on the agenda, including Russia, the Indo-Pacific area and China.
Regarding Afghanistan, Merkel said leaders will discuss what was achieved there, what can be learned and "future concepts."
The German leader said “hybrid challenges” and cyberattacks would be discussed, as well as Russia’s disinformation campaign, which affects Germany.
The situation in Ukraine and “threats in Belarus, where human rights are being kicked,” are also on the agenda, Merkel added.