The U.N. Security Council unanimously voted, 15-0, to approve a resolution calling on all parties to abide by the ceasefire, which is proving to have more pull on paper than on the ground.
Five more Ukrainian service members have been killed in the past 24 hours, Ukraine's Defense Ministry said Tuesday, the same day as the U.N. vote.
Council members issued a statement expressing "grave concern at the continued fighting in and around Debaltseve, Ukraine, which has resulted in numerous civilian casualties." The members asked for detainees to be treated "humanely."
"We've gotten used to living in an upside down world with respect to Ukraine. Russia speaks of peace and then fuels conflict. Russia signs agreements and then does everything within its power to undermine them," Samantha Power, U.S. ambassador to the United Nations, told council members.
"We are caught in a deadly feedback loop. International leaders engage in rigorous exhaustive negotiations to get Russia to commit to peace ... yet Russia's commitments have no bearing on the actions of its soldiers and the separatists they back on the ground," she said.
For its part, Russia continues to urge dialogue on political and constitutional issues.
"Since the very start of the crisis, Russia has actively called for a peaceful settlement," Vitaly Churkin, Russia's ambassador, told council members.
On Monday, Ukrainian Defense spokesman Andriy Lysenko reported five deaths from the previous day and at least 129 violations of the ceasefire since it went into effect at midnight Saturday.
And there are more signs that the international efforts to stop the bloodshed are failing.
Violence flares in hotly contested city
Heavy clashes broke out Tuesday in Debaltseve, but both the Ukrainian military and pro-Russian separatists say they are not backing down.
Debaltseve is a crucial city because it a strategic railroad hub in eastern Ukraine.
The separatists have taken over 80% of Debaltseve, said Eduard Basurin, self-declared deputy defense minister of the rebel Donetsk People's Republic.
He also said the separatists now have 60 Ukrainian prisoners of war. CNN cannot independently verify those claims.
Lysenko said Ukrainian troops are holding their positions in Debaltseve in response to the rebels' attacks.
Meeting between warring sides nixed
A planned meeting between Ukrainian officials, pro-Russian separatists and European officials about the shaky ceasefire was canceled after one of the parties failed to show up, a European diplomat familiar with the talks told CNN.
It is not clear what other reasons may have led to the cancellation.
Members of the Organization for Security and Co-operation in Europe were slated to participate in the meeting.
On Tuesday, Russia and Ukraine reiterated their agreement to let OSCE monitors observe the ceasefire in Debaltseve.
During a phone call with German Chancellor Angela Merkel, Russian President Vladimir Putin and Ukrainian President Petro Poroshenko agreed to "concrete steps" that would provide OSCE monitors access, German government spokesman Steffen Seibert said.
Russia has denied widespread allegations it is supporting the pro-Russian separatists fighting in eastern Ukraine.
Poroshenko has warned that if the separatists do not abide by the ceasefire, he will impose martial law throughout Ukraine's territory.
Civilians caught in the fighting
In the beleaguered village of Shyrokyno, Ukrainian forces struggle to keep control of the territory.
"Right now, only about a third of the village is under our control," a machine gunner named Yury told CNN's Frederik Pleitgen.
Separatists shelled Ukrainian forces with mortars, and both sides skirmished when rebels assaulted government troops with small arms and armored vehicles, said Dmytro Chalov, a spokesman for Ukraine's army in the Mariupol sector. Two Ukrainian security forces were wounded, he said.
Oleg Shiryayev, commander of Ukraine's East Corpus battalion, said the ceasefire "is a farce."
"The fighting is continuing now the way it did before," Shiryayev told Pleitgen. "They continue to attack us, shell us; they use artillery, mortars."
But it's impossible to tell which side is responsible for breaking the ceasefire in Shyrokyno.
To some residents, it doesn't matter.
"The fighting is very heavy. All the windows (of) our house are broken," one woman said. "It is very terrifying. We saved all our lives to buy our house, and now we have nothing."