KIEV - Ukraine's Western-backed president has decided to resume a military offensive against pro-Russian separatists in the country's restive east after opting not to prolong a shaky truce, a move that threatens to escalate the deadly conflict.
"After examining the situation I have decided, as commander-in-chief of the armed forces, not to extend the unilateral ceasefire," Petro Poroshenko said in an address to the nation late Monday.
"We will attack," the newly-elected leader said.
The announcement could trigger a steep escalation in the months-long conflict after a diplomatic push led by France and Germany failed to convince Kiev to extend a 10-day truce that did not quell the fighting in the rebellious eastern regions.
But Poroshenko - under pressure from the Ukrainian public to toughen his stance on the uprising - insisted that Kiev was not abandoning its peace plan altogether.
"We are even ready to return to a ceasefire at any moment. When we see that all the parties agree to enact the essential points of the peace plan," he said.
Ukraine and its Western allies accuse Moscow of fuelling the bloodshed that has claimed some 450 lives by sending arms and fighters across the porous border between the two ex-Soviet neighbours.
The Ukrainian president's announcement came a few hours after a conference call with the leaders of Russia, France and Germany, who were pushing for the ceasefire to be extended.
The French presidency had said that Kiev and Moscow were working on the "adoption of an agreement on a bilateral ceasefire," sparking expectations that the truce would continue.
But Kiev said only that all sides agreed that a new bilateral ceasefire should be discussed at a fresh round of "consultations" involving an OSCE envoy, a Russian diplomat and former Ukrainian leader Leonid Kuchma.
For its part, the Kremlin backed new indirect talks and said Putin had "stressed the importance of extending a ceasefire", to be monitored by international observers.
Prior to Monday's teleconference - the second in two days between the four leaders - French President Francois Hollande and German Chancellor Angela Merkel reiterated a European Union warning of more sanctions against Moscow unless the Kremlin explicitly pressured pro-Kremlin rebels to stop fighting.
Broader sanctions could cut off whole sectors of the Russian economy from the EU's 500 million consumers, pushing it into recession with the International Monetary Fund already warning of negligible growth.