Malaysia had been one of the nuclear-armed state's few allies until Kim Jong Nam was murdered with a banned nerve agent in Kuala Lumpur
North Korea severed diplomatic ties with Malaysia on Friday, abruptly ending a once-close relationship that soured following the assassination of Kim Jong Un's half-brother in a Kuala Lumpur airport four years ago.
Pyongyang's foreign ministry said it was responding to Malaysia's extradition of a North Korean citizen to the United States this week -- a move it labelled an "unpardonable crime" carried out under "blind obedience" to US pressure.
Malaysia had been one of the nuclear-armed state's few allies until Kim Jong Nam was murdered with a banned nerve agent as he waited to catch a flight from Kuala Lumpur.
Relations plunged after the Cold War-style hit but had started to get back on track, with Malaysia announcing plans to re-open its Pyongyang embassy.
That all changed on Friday.
North Korea's foreign ministry announced the "total severance of the diplomatic relations with Malaysia," according to state news agency KCNA, saying the citizen being extradited had been involved in "legitimate" trading activities in Singapore.
It came after a visit by US Secretary of State Antony Blinken and Pentagon chief Lloyd Austin to South Korea, the second leg of an Asian tour to bolster a united front against the North and an increasingly assertive China.
On March 9, a North Korean man named Mun Chol Myong lost his final appeal in Malaysia's top court against extradition to the US to face money laundering charges.
He had denied claims of leading a criminal group that violated sanctions by supplying prohibited items to the North and laundered funds through front companies, according to his lawyers.
Mun, in his 50s, faces four charges of money laundering and two of conspiracy to launder money. The allegations relate mainly to his work in Singapore.
There have been cases of businesses in Singapore sending luxury items, such as liquor and watches, to North Korea. Such imports are banned under sanctions imposed on Pyongyang over its weapons program.
There was a heavy police presence outside the North Korean embassy in Kuala Lumpur on Friday as hordes of journalists arrived following the announcement.
Malaysia -- which has had diplomatic relations with Pyongyang since 1973 -- said it "deeply regrets" the move and ordered all North Korean diplomats to leave the country within 48 hours.
"Malaysia denounces the decision as unfriendly and unconstructive, disrespecting the spirit of mutual respect and good neighbourly relations among members of the international community," said a foreign ministry statement.
The ministry defended the extradition of Mun, saying it was only carried out after proper legal process was followed, and criticized North Korea for pressuring it to intervene in the case.
Before the assassination of Kim Jong Nam, Malaysia and the North enjoyed particularly warm relations, but afterwards they expelled each other's ambassadors and axed a reciprocal visa-free travel arrangement for visitors.
South Korea accused the North of being behind the murder of Kim.
Two young Southeast Asian women who had smeared the poison on his face were put on trial, although their lawyers insisted the real killers were a group of North Koreans who had recruited them.
Murder charges against the pair were dropped in 2019, and they were freed.
North Korea operated embassies in about 25 countries as of December last year, including Cuba, Iran, Germany, and its key ally China, according to Seoul.
Illicit activities are known to be rampant in North Korea's foreign missions, and Pyongyang has long been accused of using them for intelligence gathering, sanctions-busting and money laundering.