North Korea has temporarily banned Malaysians from leaving its territory in a move Pyongyang claims is to ensure the safety of its diplomats and citizens in Malaysia.

The ban on Malaysian citizens leaving North Korea comes as the two countries continue to trade barbs over the alleged assassination of the North Korean leader’s half brother, Kim Jong-nam.

Malaysia’s Prime Minister Najib Razak rebuked North Korea on Tuesday as his government expelled its ambassador for casting doubt over the impartiality of the investigation into Kim’s murder.

Malaysia recalled its ambassador to North Korea last month.

The bilateral stoush is being played out to the backdrop of further regional instability and nuclear posturing from North Korea, which on Tuesday warned it was being pushed toward a nuclear war.

North Korea’s UN ambassador, Ja Song-nam, told the UN Security Council on Monday that US-South Korean military exercises were inflaming the long-standing ceasefire on the Korean Peninsula, even as the North fired four ballistic missiles into the sea off Japan’s north-west.

North Korea’s foreign ministry notified the Malaysian embassy in Pyongyang of the travel ban on Tuesday, saying it hoped Kim’s murder investigation would be swiftly and fairly resolved in order to develop bilateral ties with Malaysia, the North’s KCNA news agency reported.

Prime Minister Najib called on North Korea to immediately release all its citizens.

“This abhorrent act, effectively holding our citizens hostage, is in total disregard of all international law and diplomatic norms,” he said in a statement, adding he had summoned an emergency meeting of the National Security Council.

Mr Najib instructed Malaysian authorities “to prevent all North Korean citizens in Malaysia from leaving the country until we are assured of the safety and security of all Malaysians in North Korea”.

Malaysian police also sealed off the North Korean embassy in Kuala Lumpur to ascertain the number of officials inside, Deputy Home Minister Nur Jazlan Mohamed said.

Kim Jong–nam was murdered while traveling to his home in Macau. Photo: Getty

The lockdown came as two North Koreans wanted for questioning over Kim’s murder were reportedly hiding in the North Korean embassy in Kuala Lumpur.

Mr Khalid said North Korean authorities were not cooperating with the investigations.

Kim, who had criticised the regime of his family and his half-brother Kim Jong-un, died after two women allegedly smeared VX nerve agent, a chemical described by the United Nations as a weapon of mass destruction, across his face.

‘Brink of nuclear war’

North Korea has warned that the joint US-South Korean military exercises – which it described as “the most undisguised nuclear war manoeuvres” – are driving the region toward “nuclear disaster”.

North Korea’s Ja Song-nam said in a letter to the UN Security Council that the US was using nuclear-propelled aircraft carriers, nuclear submarines, nuclear strategic bombers and stealth fighters in the exercises that began on March 1.

“It may go over to an actual war,” Ja warned.

“Consequently, the situation on the Korean Peninsula is again inching to the brink of a nuclear war.” 

The US, Japan and South Korea have voiced alarm over the missile tests

North Korean leader Kim Jong-un, meanwhile, supervised the test launches of four missiles by an army unit commissioned with attacking US military bases in Japan, the country’s official news agency reported.

The test saw the missiles fall into the sea 300 to 350 kilometres off the coast of Japan.

The US and Japan have requested an urgent meeting of the UN Security Council in response to the launches.

A spokesman for Nikki Haley, US ambassador to the UN, said the request for a meeting was made in coordination with South Korea. No date for the meeting has been set.

– with agencies