The Ukrainian government and pro-Russia rebels meeting in Minsk have signed a preliminary protocol to start a ceasefire, Ukrainian President Petro Poroshenko says.
He said that the truce would start at 15:00 GMT. The announcement came after reports of further clashes in the east.
Representatives of Russia, the rebels and the Ukrainian government during the Minsk talks.
Western countries are meanwhile working on further sanctions against Russia.
The West accuses Russia of sending arms and troops to back the rebels in eastern Ukraine. Moscow denies this.
The talks in Minsk, capital of Belarus, involve former Ukrainian President Leonid Kuchma, Russian ambassador to Ukraine Mikhail Zurabov and leaders of the self-proclaimed “people’s republics” in Donetsk and Luhansk.
They come after Russian President Vladimir Putin put forward a seven-point peace plan.
The plan includes a halt to “active offensive operations” by the Ukrainian military and pro-Russia rebels, international ceasefire monitoring, unconditional prisoner exchanges and humanitarian aid corridors.
As the peace talks in Minsk began, fighting in eastern Ukraine continued.
Ukrainian government forces and volunteers are trying to hold on to Mariupol on the Azov Sea. The BBC’s Fergal Keane, in Mariupol, tweeted that pro-Russia forces seemed to be hitting Ukrainian positions some 4km (2.5 miles) outside the city.
Large plumes of smoke could be seen as Ukrainian artillery fired back, he says. Ukrainian fighter jets also hit rebel positions.
The Minsk peace talks coincided with Nato’s summit in Wales, where leaders agreed on a new “spearhead” military force, able to deploy to trouble spots in a matter of days.
The decision came amid growing Nato concern at the Ukraine crisis – in particular Russia’s role – and the rise of Islamic State militants in Iraq and Syria.
