Media playback is unsupported on your device Media caption S Korea 'deploys warships to track N Korea missiles'

North Korea has told foreign embassies in Pyongyang it cannot guarantee their safety in the event of conflict, and to consider evacuating their employees.

Both Russia and the UK said they had no immediate plans to evacuate their embassies in the North Korean capital.

The North's move comes amid threats to attack US and South Korean targets.

South Korea has reportedly deployed two warships with missile defence systems after the North was said to have moved at least one missile to its east coast.

Military officials told South Korean media the two warships would be deployed on the east and west coasts.

What Pyongyang is daily threatening is a fantasy. If they did any of it, this would be suicidal Aidan Foster-Carter, Korea analyst Mobilising the propagandists

Seoul has played down the North's missile move: It said the move may be for a test rather than a hostile act.

For its part, the US said it would not be surprised 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."

Russia 'deeply concerned'

British diplomats said on Friday the North had asked them to respond by 10 April on what support the embassy would need in the event of any evacuation - and they were considering their moves.

"We are consulting international partners about these developments," said a Foreign and Commonwealth Office statement. "No decisions have been taken, and we have no immediate plans to withdraw our Embassy."

Russian Foreign Minister Sergei Lavrov said Moscow was "deeply concerned about the escalation of tension, which for now is verbal".

Media playback is unsupported on your device Media caption Footage has been shown on state television of North Korean President Kim Jong-un watching a military drill

"We want to understand the reasons behind this offer," he said. "We were interested in finding out whether this was a decision taken by the North Korean leadership to evacuate embassies, or just an offer."

Anecdotal reports from Pyongyang suggest the mood there is calm, and many believe North Korea is deliberately trying to create a sense of crisis, says the BBC's Lucy Williamson in Seoul.

One of the US targets named by Pyongyang was the Pacific island of Guam, which hosts a US military base.

On Thursday, the US confirmed it would deploy a missile defence system to Guam in response to the threats.

Aegis missile defence system Allows warships to shoot down enemy ballistic missiles while they are still in space

Interceptors are fired to hit missiles before they re-enter the atmosphere

The US, South Korea and Japan all have Aegis capability Business as usual in South Guide: Missile defences in the region

South Korea's foreign minister told MPs on Thursday that the North had moved a missile to the east coast, which is the location for previous military tests.

Unconfirmed reports on Friday said the North had moved two missiles - thought to be mid-range Musudans, which are untested in flight but are thought to have the capacity to reach as far as Guam - and loaded them on to launchers.

Yonhap, the South Korean news agency, said that two warships equipped with Aegis defence systems would monitor the situation.

'Turn down volume'

Despite North Korea's belligerent rhetoric, it has not taken direct military action since 2010, when it shelled a South Korean island and killed four people.

But in recent weeks it has threatened nuclear strikes and attacks on the US and South Korea.

It has announced a formal declaration of war on the South, and pledged to reopen a mothballed nuclear reactor in defiance of UN Security Council resolutions.

Many of North Korea's angry statements have cited the annual military exercises between US and South Korean forces as provocation.

The US flew nuclear-capable B2 and B52 bombers over the South as part of the drill, and has since deployed warships with missile defence systems to the region.

Regional papers reflect on crisis In South Korea Chosun Ilbo says: "The military has pledged to maintain a solid defence amid increasing threats from North Korea, but incident after incident shows how empty that pledge is."

Joong Ang Daily writes: "The escalation of tension by the North has hardly affected the South. Pyongyang's provocations are aimed at consolidating Kim Jong-un's power base at home." In Japan According to Yomiuri Shimbun: "Kim should be keenly aware that the pursuits of nuclear armament and economic reconstruction are incompatible."

Asahi Shimbun writes: "The United States and its two regional allies, Japan and South Korea, should start working closely together in serious efforts to figure out the best way to deal with North Korea." How potent are threats? Missile programme

North Korea's official media say the US is surrounding the peninsula with a nuclear threat from land, sea and air.

Quotes from unnamed Pentagon officials suggest Washington is now questioning whether some of its actions may have contributed to the tension, with CNN quoting one official as saying the US would try to "turn the volume down" on its rhetoric.

Meanwhile, retired Cuban leader Fidel Castro has urged restraint on the Korean Peninsula in his first newspaper "reflections" piece for nine months.

Writing of the wider impact that a nuclear war could unleash in Asia and beyond, Mr Castro said Havana had always been and would continue to be an ally of North Korea, but asked it to consider the interests of its friends.

In recent weeks, the North has shut down an emergency military hotline between Seoul and Pyongyang and stopped South Koreans from working at a joint industrial complex in the North.

The Kaesong complex, one of the last remaining symbols of co-operation between the neighbours, is staffed mainly by North Koreans but funded and managed by South Korean firms.