The United States says it is "gravely concerned" over the deteriorating situation in and around the eastern Ukrainian town of Debaltseve, where pro-Russian rebels are refusing to honor an internationally brokered cease-fire.
The U.S. State Department, in a statement Monday, said 129 rebel cease-fire violations have been recorded since late Sunday, along with five deaths.
Spokeswoman Jen Psaki described the violations reported by the Kyiv government as "aggressive actions" that threaten the cease-fire agreement announced last week by Russia, Ukraine, Germany and France, which calls for government and separatist forces to withdraw heavy weapons.
Rebel commander Eduard Basurin said Sunday that separatist fighters would not observe the truce in Debaltseve, and there were no signs early Tuesday that he or other rebel leaders would reverse that decision. Basurin said no such withdrawal would occur until 48 hours after shelling stopped.
Earlier Monday, separatists offered Ukrainian forces safe-passage out of Debaltseve if they laid down their arms. But Ukraine promptly rejected the idea and said the town lies within its territory under the truce negotiated at the 4-nation summit in Minsk, Belarus. The devastated town has seen major fighting constantly since earlier truce efforts failed last month.
German Chancellor Angela Merkel, French President Francois Hollande and Poroshenko voiced concern Monday about the ongoing fighting in Debaltseve. They called for European security monitors to be given access to the city, which the rebels have blocked.
"The situation is fragile," Merkel said, "but that was certainly to be expected, given Debaltseve."
Ukraine military spokesman Andriy Lysenko told reporters in Kyiv that its forces had been hit 112 times since the official start of the cease-fire after midnight Saturday.
"At the moment, we are not ready to withdraw heavy weapons," Lysenko said.
Even as the rebels offered to let as many as 7,000 of Kyiv's forces leave Debaltseve, its fighters vowed to take control of the city and its railway linking the rebel strongholds of Luhansk and Donetsk.
Map of Ukraine showing Donetsk, Luhansk, Debaltseve, Vuhlehirsk, Dokuchaievsk, and Horlivka
"You can hear there is no ceasefire,'' said a rebel fighter
with a black ski mask who gave his name as Scorpion, his nom de guerre, and blamed the fighting on Kyiv's forces. "Debaltseve is our land. And we will take Debaltseve.''
The separatists offered Kyiv's troops safe-passage out of Debaltseve, but only if they laid down their arms. A spokesman for Ukraine's military, Vladislav Seleznyov, told Reuters he rejected the proposal.
Kyiv insists that the latest truce deal put Debaltseve under government control.
The Organization for Security and Cooperation in Europe said on Sunday its monitors in eastern Ukraine were turned back from Debaltseve.
Other flashpoints in the latest fighting Monday included the regional centers of Donetsk and Luhansk as well as the towns of Dokuchaievk, Vuhlehirsk and Horlivka.
Next stage of cease-fire
Withdrawal of heavy weapons from the frontlines in Ukraine is set to begin at midnight Monday under the terms of the cease-fire, negotiated late last week in Minsk, Belarus, by the the leaders of Germany, France, Ukraine and Russia.
But a Ukrainian military spokesman said such a move would be unlikely.
"One hundred and twelve attacks are not an indicator of a cease-fire. At the moment we are not ready to withdraw heavy weapons,'' Andriy Lysenko told a news briefing in Kyiv.
In another development, the European Union included two Russian deputy defense ministers on its latest Ukraine sanctions list Monday, hitting them with travel bans and asset freezes for their role in the conflict.
They are among 19 new people and nine entities the EU has sanctioned due to the Ukraine crisis.
Russia said that it would respond "appropriately" to the latest EU measures.
Ukraine and a host of Western governments accuse Moscow of stoking the rebellion in Ukraine's Russian-speaking east with arms and fighters. The Kremlin has repeatedly denied providing direct support, and claims that Russian troops seen fighting alongside rebels are volunteers.