North Korea has urged foreign diplomats in the country to consider evacuating their diplomatic missions over rising tensions in the Korean Peninsula.

Pyongyang, through a "diplomatic circular", has made it clear it will be unable to protect the foreign missions after 10 April as a full-fledge war could break out anytime.

North Korea's foreign ministry said: "the current question was not whether, but when a war would break out on the peninsula" due to the "increasing threat from the United States", according to Chinese news agency Xinhua, which has a bureau in Pyongyang.

The US, Britain and Russia have all confirmed the latest round of warnings from Pyongyang.

Washington has neither a consulate nor an embassy on North Korean soil as it does have diplomatic relations with the defiant nation. The US rely on the Swedish embassy in Pyongyang to provide emergency or consular services to a small number of US citizens in North Korea, who are either non-governmental workers or tourists.

The US State Department spokesperson Victoria Nuland said: "We have been in touch with the Swedes, our protecting power in the DPRK (North Korea), because obviously if they were to change their status, we would have to inform American citizens in the DPRK. At this point, we have no reason to believe that they will make any changes."

Nevertheless, when asked about a possible military attack by Pyongyang, Nuland added: "I am not in a position to have a crystal ball on that kind of thing. Obviously, we're going to take prudent precautions."

Britain, which has an embassy in Pyongyang, confirmed it has "no immediate plans" to evacuate its staff.

The UK Foreign Office said: "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."

According to reports, Moscow has also indicated it is examining Pyongyang's latest warning but it has no intentions to withdraw its staff members any time soon. Foreign diplomats may hold a meeting later in the day in Pyongyang to discuss North Korea's proposal.

Seoul is bewildered by the latest announcement from North Korea as it continues to reflect on the seriousness of these threats.