German Chancellor Angela Merkel urged Russian President Vladimir Putin in a phone call on Friday to help defuse the crisis in Ukraine and halt the stream of weapons and armed personnel into the country, her office said in a statement on Friday.
"The chancellor expressed her concern about the situation in the east of Ukraine. In view of the need for an urgent ceasefire she urged the president to help de-escalate the situation and in particular to halt the stream of weapons, military advisers and armed personnel into Ukraine," spokesman Steffen Seibert said.
She also expressed her hope that a convoy of aid would reach its target quickly, in order to stop people's suffering.
The foreign ministers of Russia, Ukraine, Germany and France are due to meet in Berlin on Sunday.
Merkel has called Putin repeatedly, seeking to draw on traditionally closer relations between Berlin and Moscow than other Western capitals, to appeal to him to ease the crisis over a pro-Russian separatist uprising in eastern Ukraine.
She said this week Germany had a strong interest in a sound and constructive relationship with Moscow, and she was always prepared to keeping talking to the Russian president.
On Friday, Ukraine said its artillery destroyed part of a Russian armoured column that entered its territory overnight and said its forces came under shellfire from Russia in what appeared to be a serious military escalation between the former Soviet republics.