Ukraine’s government launched air strikes and deployed paratroops against pro-Russian militants who seized the city of Donetsk’s international airport as Moscow said it was willing to hold talks with Petro Poroshenko, the new president.

The offensive yesterday, which brought fighting to within 10km of the centre of the biggest city in Ukraine’s industrial east, came just hours after Mr Poroshenko’s emergence as the clear winner of Sunday’s election. It also presented an immediate test to Russia’s willingness to engage with Kiev after an election that was hailed in Europe and the US as a chance to resolve the Ukraine crisis.

Earlier yesterday, the Russian government issued a cautious endorsement of Sunday’s vote, in which Mr Poroshenko won 54 per cent with more than 76 per cent of the ballots counted. But it warned him against resuming military operations, which Moscow’s foreign ministry said would be a “colossal mistake”.