Kiev: German Chancellor Angela Merkel was Monday to brief US President Barack Obama on the latest peace plan for Ukraine ahead of a four-way summit aimed at ending 10 months of bloodshed.
Foreign ministry officials from Ukraine, Russia, Germany and France were due to hold a preparatory meeting in Berlin after leaders agreed to push for the key meeting on a new peace deal Wednesday in Minsk, the capital of Belarus.
Russian President Vladimir Putin, however, warned that a "number of points" still needed to be hammered out before the meeting could take place.
Meanwhile, Merkel flew to Washington to discuss a European-brokered peace initiative with President Barack Obama in the latest leg of a frantic diplomatic push to stop the conflict escalating as the White House mulls supplying weapons to Kiev.
The latest peace bid is being billed as a last-ditch effort to halt the spiralling bloodshed in east Ukraine that has already cost at least 5,400 lives.
Fresh fighting over the past 24 hours between government forces and pro-Russian rebels left at least seven civilians and nine Ukrainian troops dead, Kiev said.
Separatists told AFP that a munitions factory was hit as heavy shelling echoed around the rebel stronghold of Donetsk.
In a four-way telephone talk on Sunday Putin, Merkel, Ukraine President Petro Poroshenko and French leader Francois Hollande floated the summit as a the next step to finding a "comprehensive settlement" to end the conflict, Berlin said.
Merkel and Hollande have ramped up their push for peace in recent days, jetting to Kiev first for talks with Poroshenko and then to Moscow to meet with Putin, who the West accuses of masterminding the violence.
The Ukrainian government said after the phone call that the four leaders expected their efforts to lead to "an immediate and unconditional bilateral ceasefire".
A previous peace deal agreed in Minsk in September has been largely ignored, with fighting escalating in recent weeks as the rebels push further into government-held territory.Wrangling at the meeting in Berlin later Monday afternoon is expected to be intense as deputy foreign ministers lay the ground for the leaders` summit.
"Our principal objective is to prepare the elements for a document that is acceptable to Ukraine," Olexiy Makeyev, a senior Ukrainian foreign ministry official heading to the meeting, told AFP.
One major sticking point is thought to be whether rebels are handed control over territory they have seized in recent weeks, with Kiev adamant that a demarcation line agreed in September should not be shifted.
Hollande has told French television the proposal includes the creation of a 50- to 70-kilometre (31- to 43-mile) demilitarised zone around the current line.
Monitors from the Organization for Security and Co-operation in Europe (OSCE), representatives from Kiev and Moscow and the rebels are also set to hold a meeting Tuesday, Ukraine says.In Washington, Merkel touched down Sunday for talks with Obama as the worsening violence confronts them with a choice between pursuing the risky peace talks or throwing more weapons into the war.
At home the White House is facing increasing calls to supply the outmatched Ukrainian army with more weapons to shore up its faltering defences.
But Merkel and many European nations believe weapons could not overturn the military mismatch between Ukraine and the might of the Russian army, and would simply escalate the conflict.
"I think that the progress Ukraine needs won`t be achieved with even more weapons," Merkel told a security conference in Munich on Saturday.
US Secretary of State John Kerry has dismissed talk of a rift with Europe on the issue.
"Let me assure everybody, there is no division, there is no split," Kerry said in Munich.
Putin, meanwhile, is in Egypt Monday for a two-day visit on in what experts say is in part a bid to show he has not been internationally isolated by the Ukraine crisis.
"It is evident that the crisis will continue until the Ukrainians themselves agree with each other," he said in an interview with Egyptian state newspaper Al-Ahram.
Ukraine and its Western allies accuse Moscow of sending troops and weapons to spearhead the rebellion, but Moscow denies the allegations despite the rebels acquiring heavy weaponry.
Kiev says the rebels are massing tanks, armoured vehicles and rocket launcher systems for further offensives.
The town of Debaltseve -- mid-way between the rebel centres of Donetsk and Lugansk -- has been the focus of fierce fighting for over a week as insurgents try to encircle government troops holding the strategic railway hub.