The UK foreign minister Liz Truss on Monday said the British ambassador to Ukraine Melinda Simmons had left the Eastern European country due to a "serious security situation" there.

"Our ambassador has left Ukraine because of the serious security situation," Reuters quotes Truss to have told a parliamentary committee.

The envoy's departure from Ukraine comes as Russia continues its military operation in the country.

Various countries have reportedly closed their embassies in Ukraine, including Japan, U.S., Canada, Algeria and Australia.