North Korea asked foreign diplomatic missions on Friday to consider moving their staff out of their embassies, warning it cannot guarantee their safety after April 10 in the event of a conflict.
The move came amid rising tensions on the Korean peninsula following Pyongyang's nuclear threats.
Russian Foreign Minister Sergei Lavrov said that Moscow was consulting with China and the United States and several other countries over the warning, according to Russian news agencies.
"We are in close contact with our Chinese partners as well as the Americans, the South Koreans and the Japanese," Interfax quoted Lavrov as saying during a visit to Uzbekistan.
There were "many factors" that needed clarification, Lavrov said.
About two dozen countries have embassies in North Korea and there were no immediate plans by any one of them to evacuate their staff.
Britain appeared to dismiss the warning as an attempt by Pyongyang to give an impression that it was in imminent danger of an attack by the U.S.
"The DPRK [Democratic People's Republic of Korea] has responsibilities under the Vienna convention to protect diplomatic missions, and we believe they have taken this step as part of their continuing rhetoric that the U.S. poses a threat to them," a Foreign Office spokeswoman in London said in a statement.
"We are considering next steps, including a change to our travel advice."
U.N. 'deeply concerned'
The United Nations said one of its representatives had joined other foreign diplomats at a meeting in Pyongyang on Friday called by the North Korean foreign ministry concerning the safety of foreign diplomats.
U.N. spokesman Martin Nesirky said in a statement in New York that the world body has no plans to evacuate its staff from North Korea.
He hastened to add that U.N. Secretary-General Ban Ki-moon "remains deeply concerned about escalating tensions on the Korean peninsula."
North Korea's warning to foreign embassies came amid reports about the possibility of another missile launch by the hardline North Korean communist government of Kim Jong Un.
South Korea's Yonhap news agency reported that two intermediate Musudan missiles had been transported by train earlier in the week and loaded on vehicles equipped with launch pads and hidden in underground facilities near North Korea's east coast.
"The North is apparently intent on firing the missiles without prior warning," Yonhap quoted an official as saying.
The Musudan has never been tested, but is believed to have a range of around 3,000 kilometers (1,860 miles), which could theoretically be pushed to 4,000 with a light payload, according to Agence France-Presse.
That distance would cover any target in South Korea and Japan, and possibly even reach U.S. military bases located on the Pacific island of Guam, the AFP report said.
The United States has said it will send missile-interceptor batteries to protect its bases on Guam, a U.S. territory some 3,380 kilometers (2,100 miles) southeast of North Korea and home to 6,000 American military personnel.
North Korea is not yet capable of mounting a nuclear device on a ballistic missile that could strike U.S. bases or territory, according to most experts.
The fresh tensions marked an escalation in nuclear-armed North Korea's month-long standoff with South Korea ally the United States.
The North said earlier this week it would restart a long-shuttered Yongbyon nuclear reactor, the latest in a catalog of actions by young leader Kim Jong Un's regime since it fired a long-range rocket in December and conducted its third nuclear test in February, drawing international sanctions, including from ally China.
On Wednesday, Pyongyang barred South Koreans from entering a key Seoul-funded joint industrial zone in Kaesong along the North's side of the border and warned that it had finalized plans for "merciless" military strikes on the United States.
North and South Korea have not allowed previous crises to stifle the industrial park's operations, seen as a living example of cooperation between the two countries, which have technically been at war for the last 60 years, as the 1950-53 Korean War ended with an armistice rather than a formal peace treaty.
Last month, however, North Korea said that it would no longer be bound by the truce, in protest against South Korea’s joint military exercises with the United States, which has deployed nuclear-capable B-2 stealth bombers and F-22 stealth fighters and two Aegis anti-missile destroyers to South Korean air and sea space.
Reported by RFA's Korean Service. Written in English by Parameswaran Ponnudurai.