Ukraine’s president has told the BBC his country is now in a “real war” with Russia – and that Ukrainians should prepare for a Russian offensive.
Petro Poroshenko told the BBC’s Fergal Keane he did not trust his Russian counterpart, Vladimir Putin, but had no option but to negotiate with him.
The Kremlin said it did not trust Mr Poroshenko either and accused Ukraine of “broken commitments”.
Meanwhile Ukraine has charged two men it accuses of being Russian soldiers.
Russia denies Western accusations that it has sent regular troops and armour to help rebels in eastern Ukraine.
The United Nations says at least 6,000 people have been killed since fighting started in eastern Ukraine in April 2014.
‘We should be ready’
Mr Poroshenko said he believed Russia was preparing for “an offensive” in the summer.