Foreign embassies in Pyongyang have been told by North Korea that their safety could not be guaranteed in the event of conflict, and they should consider evacuating their staff.
Both Russia and the UK denied any immediate plans to evacuate their embassies in the North Korean capital.
The country's move comes following threats of attack against US and South Korean targets.
According to reports, South Korea had deployed two warships with missile defence systems following North Korea saying it had moved at least one missile to its east oast.
According to military officials who spoke to media, the two warships would be deployed on the east and west coasts.
South Korea has played down the North's missile move saying the move may be for a test rather than a hostile act.
The US meanwhile, said it would not come as a surprise if North Korea were to conduct a new missile test, with White House spokesman Jay Carney telling reporters: "We have seen them launch missiles in the past."
Reuters cited a South Korean government official expressing surprise over North's appeals to diplomats. The agency's report quoted an unidentified official who asked not to be identified as saying that as North Korea had many reasons behind the latest threats, it was hard to define what was its real intention.
He added, it might have intensified these threats to strengthen the regime internally or to respond to international community.
There was no sign of tension in Seoul, with traffic operating normally this morning and no extra police seen.
The South Korean media reports yesterday said North Korea had placed two of its intermediate-range missiles on mobile launchers and hidden them on the east coast, a move that could threaten Japan or US Pacific bases.
Meanwhile, Britain's Foreign Office said, it believed the North Koreans had taken the step as part of their continuing rhetoric that the US posed a threat to them.
Adding that it had "no immediate plans" for evacuation of its embassy, the UK accused the North Korean government of raising tensions "through a series of public statements and other provocations''.
US state department spokeswoman Victoria Nuland said this was just an escalating series of rhetorical statements.
Asked if the US had received any instructions from the Swedes on the small number of US aid workers or tourists who could be in North Korea, she said there had been no indication Sweden would heed Pyongyang's warning.