Ukraine was set today to sign a Kremlin-backed truce with insurgents that could halt nearly five months of bloodshed but whose failure would unleash new Western sanctions against Russia.
But even before the peace talks opened in the Belarussian capital Minsk, renewed combat was erupting on the edge of the strategic port of Mariupol, the latest flashpoint in the conflict that has plunged East-West relations to a post Cold War low.
AFP correspondents also reported heavy bombardments overnight in Donetsk, the main rebel-held city in eastern Ukraine, further highlighting the fragility of any ceasefire deal.
The seven-point blueprint -- unveiled by Russian President Vladimir Putin this week after telephone talks with his Ukrainian opposite number Petro Poroshenko -- would require government forces to retreat from much of the industrial regions of Donetsk and Lugansk.
But Poroshenko said he held out "very careful optimism" that peace could return to the splintered ex-Soviet country, and vowed to order a halt to hostilities once the pact is signed at the European-brokered talks.
"The only thing we need now for peace and stability is just two main things," Poroshenko said yesterday on the sidelines of the NATO summit in Wales.
"First, that Russia withdraw its troops; and second, to close the border. If that happens, I assure you that Ukraine (will) find a peace solution within days."
NATO leaders voiced strong support for Ukraine at a two-day meeting that has focused largely on Russia's new expansionist threat.
EU and US officials have said sanctions against Russia would be announced today in response to a major escalation of Moscow's military support to the rebels.
But Britain's foreign secretary said today the measures could be lifted in the event of a ceasefire.
"If there is a ceasefire, if it is signed and if it is then implemented, we can then look at lifting sanctions off," Philip Hammond said at the NATO summit.
Any truce deal would however leave the political status of Ukraine's economically-vital east uncertain and expose Poroshenko to charges that he had signed his government's surrender to Russian troops.
Poroshenko had vowed after his May election to crush the rebellion -- a mission that seemed on the verge of success until NATO reported last week that more than 1,000 Russian soldiers had flooded across the border with heavy weapons in support of a sweeping counter-offensive by the insurgents.
