Pro-Russian rebels in Ukraine claim to have surrounded the strategic town of Debaltseve which has seen intense fighting for over a week.
It comes after US President Barack Obama said he had not ruled out supplying weapons to Ukraine's government if diplomatic efforts fail.
However, German Chancellor Angela Merkel continues to oppose arming Kiev and is pushing a new peace deal for the conflict in the east of Ukraine.
Russia, Ukraine, France and Germany are due to hold talks in Belarus on Wednesday.
Roland Oliphant is the Telegraph's Moscow correspondent - he says the Kremlin would be likely to escalate the situation if Washington sent weapons to Kiev.
IN: "Moscow....
OUT: ...a step."
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Roland Oliphant is the Telegraph's Moscow correspondent - he says no one will go into the Minsk talks expecting a major breakthrough.
IN: "Hopes are....
OUT: ...this time."
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Roland Oliphant is the Telegraph's Moscow correspondent - he says Russia's population appears to back President Putin on the Ukrainian issue.
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OUT: ...United States."
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