Ukrainian forces have withdrawn from the airport of the eastern city of Luhansk following clashes with pro-Russian rebels, military officials say, reports GHN based on BBC.
The announcement came after the two sides were engaged in all-night fighting.
Russian Foreign Minister Sergei Lavrov has urged negotiators meeting in the Belarus capital, Minsk, to make an "immediate ceasefire" their priority.
Some 2,600 people have died in eastern Ukraine since fighting began in April.
The conflict broke out after Russia's annexation of Ukraine's southern Crimea peninsula in March.
The rebels have been gaining ground on Ukrainian forces in recent days, in both the Luhansk and Donetsk regions, and further south around the port of Mariupol.
Ukraine and the West blame Russian military support for the rebel advances, saying armoured columns have crossed the border - allegations rejected by Russia's President Vladimir Putin.
He has accused European leaders of ignoring the Ukrainian army "directly targeting civilians".
On Sunday, he said the issue of "statehood" for eastern Ukraine needed to be discussed to ensure the interests of local people were "definitely upheld".
In other developments:
• President Putin urged the European Union to show "common sense" and not to engage in mutually destructive sanctions, in his first reaction to the threat of new sanctions over Ukraine
• German Chancellor Angela Merkel acknowledged that further sanctions against Russia could aversely affect her country's economy, but said "accepting Russia's behaviour [was] not an option"
• Russia's energy minister said Russia and Ukraine had agreed to hold talks on 6 September to resolve the gas crisis, adding that the EU had yet to confirm whether it would send a representative.
