Ukraine's new Western-backed leader sought urgent talks with Russian President Vladimir Putin yesterday after separatist rebels shot down an army helicopter despite orders from their own commander to observe a fragile truce.
The death of nine servicemen outside the pro-Russian stronghold city of Slavyansk and loss of two other soldiers in militia attacks prompted Ukrainian President Petro Poroshenko to threaten to unleash a powerful new military campaign in the industrial east.
Poroshenko's warning dealt a crushing blow to hopes of the sides mediating an end to 11 weeks of fighting that has killed more than 435 people and brought the ex-Soviet nation to the brink of collapse.
Kiev's temporary ceasefire was picked up by separatist commanders on Monday but was due to expire tomorrow morning after just one round of inconclusive and indirect talks.
Putin urged both sides to extend the truce and further asked senators to revoke his March 1 authorisation to invade his western neighbour in a self-proclaimed bid to "protect" ethnic Russians from the nationalists now in power in Kiev. Russia's rubber-stamp upper chamber approved Putin's request yesterday in a 153-1 vote.
But Kiev and Washington still accuse Putin of covertly arming the rebels in retaliation for the February ouster of a pro-Russian administration that abruptly ditched a historic EU agreement and preferred closer ties with Moscow instead.
Poroshenko will sign the final chapters of that pact in Brussels tomorrow despite the strong likelihood that Russia will follow up a cut in gas deliveries it imposed on June 16 with punishing new trade restrictions.