Britain on Friday reminded North Korea that it has a responsibility to protect embassies and said it was "considering next steps", after Pyongyang said foreign diplomats should consider pulling out amid soaring nuclear tensions.

A spokeswoman for the Foreign Office said that like Russia, Britain had been told by North Korean authorities that it may wish to evacuate its mission in Pyongyang.

"Their communication said that from April 10, the North Korean government would be unable to guarantee the safety of embassies and international organisations in the country in the event of conflict," the spokeswoman said.

"Our understanding is that the North Koreans were asking whether embassies are intending to leave, rather than advising them to leave."

She added: "The DPRK has responsibilities under the Vienna Convention to protect diplomatic missions and we believe they have taken this step as part of their country's rhetoric that the US poses a threat to them.

"We are considering next steps including a change to our travel advice."

The North Korean foreign ministry has suggested that Russian diplomats should "examine the question of evacuating employees", a Russian embassy spokesman told news agencies.

North Korea, incensed by UN sanctions and South Korea-US military drills, has issued a series of apocalyptic threats of nuclear war in recent weeks.