A new peace roadmap aimed at ending the 10-month war between Ukraine and pro-Moscow rebels was agreed in Belarus Thursday, but Germany's Chancellor Angela Merkel warned that "big hurdles" remained.
Russian President Vladimir Putin emerged from the summit in the Belarussian capital Minsk, saying he, Merkel, French President Francois Hollande and Ukrainian President Petro Poroshenko had agreed on the "main" points.
Putin said a ceasefire would take effect at midnight Kiev time on Sunday (2200 GMT on Saturday) and that heavy weapons would be withdrawn from frontlines of the conflict, which has already killed at least 5,300 people and driven a million people from their homes.
Hollande, described the deal as "a comprehensive political solution", while Merkel spoke only of a "glimmer of hope".
"I have no illusions. We have no illusions," she said, adding that "much work" remained.
Hollande, Merkel and Poroshenko flew from Minsk to Brussels for a European Union summit, where the French leader said that it was essential to keep up pressure to ensure the accord's success.
"The next few hours will be decisive as it could go either way," Hollande said at an EU summit in Brussels fresh from the peace talks in Minsk, adding: "We will have to remain vigilant, to maintain the pressure and to press ahead."
British Premier David Cameron said Putin should not expect any change to current sanctions against Moscow by the 28-nation EU unless he really changed his behaviour.
"If this is a genuine ceasefire then that would be welcome but what matters most of all is actions," he added.
- Toll mounts -
The roadmap -- meant to ease a crisis that has plunged the West and Russia into their bitterest dispute since the Cold War -- was signed by the so-called "contact group".
This comprises the pro-Russian separatist leaders, Russian and Ukrainian envoys, and European mediators from the OSCE.
A previous truce signed in Minsk last September quickly collapsed.
The latest talks were seen as a last opportunity for European leaders to save nearly bankrupt Ukraine from ever-widening defeats at the hands of rebels said by Kiev and the West to be armed and trained by Russia.
Even as the deal was agreed, Kiev and rebel sources said fighting over the last 24 hours had killed 14 civilians and two Ukrainian soldiers.
The Ukrainian government also accused Russia of deploying another 50 tanks across the border overnight, with fighting expected to continue around disputed railway hub Debaltseve, which rebels claim to have surrounded.
Putin said that up to 8,000 Ukraine troops were surrounded at Debalseve and rebels expected them to lay down their arms.
The Ukrainian military however denied the troops were blocked but said fighting was continuing ahead of the ceasefire.
In rebel-held Donetsk, weary residents expressed little optimism.
- Money and guns -
"I don't believe in it at all," said Lyubov, 62, who would not give her last name. "Every time they sign an agreement, they say one thing and do another. I no longer trust anyone."
Beset by war and corruption, Ukraine's pro-Western government is struggling to enact legal and economic reforms that would help steer the former Soviet republic out of Russia's sphere of influence and into Western institutions.
The Kiev government got a major boost Thursday with the announcement by IMF chief Christine Lagarde of a new financial rescue plan worth $17.5 billion.
In total, Ukraine will receive $40 billion (35 billion euros) in assistance over four years coupled with bilateral loans from other sources, Lagarde said, helping to stabilise Kiev's finances after 10 months of conflict in the east.
The fate of Ukraine, however, may be decided on battlefields in the east, where heavily armed rebels have recently made big gains against outgunned government forces.
The new Minsk agreement is broadly similar to the first one, except that the new heavy weapons-free zone will be 50 to 70 kilometres (31-43 miles) wide, depending on the range of the weapon, double the width of the buffer zone agreed in September.
Kiev will also begin retaking control over the approximately 400 kilometre (250 mile) stretch of Russia's border with rebel-held Ukraine, but only after local elections are held.
The border is entirely under Russian and pro-Russian rebel control and is used, according to Kiev, as a conduit for separatist supplies. The Kremlin denies this but has opposed Ukraine being allowed to regain control of the frontier.
While heavy weapons must be withdrawn, troops and rebels can remain where they are, handing rebels de facto control of the roughly 500 square kilometres of territory they've gained in recent weeks.
Separatist-held territories will be granted a degree of autonomy to be established through talks, and the right to decide which language they use.