Kyiv said Wednesday it was severing relations with North Korea, as Pyongyang confirmed it was formally recognising two self-proclaimed pro-Russian republics in eastern Ukraine.

North Korea's recognition of the so-called Donetsk People's Republic and Lugansk People's Republic came after another Russian ally, Syria, made the same move last month.

The Ukrainian foreign ministry in a statement denounced North Korea's decision to recognise territories Kyiv described as "temporarily occupied by Russia".

"In response... Ukraine announces it is cutting diplomatic relations with the Democratic People's Republic of Korea," the statement said.

"Russia no longer has any allies in the world, with the exception of countries that depend on it financially and politically," Ukrainian Foreign Minister Dmytro Kuleba said, according to the statement.

Kuleba said Russia had appealed to North Korea to recognise the territory in a move that "speaks more about Moscow's toxicity than Pyongyang's".

Russia recognised the self-proclaimed republics shortly before it launched its invasion of pro-European neighbour Ukraine on February 24.

North Korean state media KCNA said Thursday morning the country "decided to recognise the independence of the People's Republic of Donetsk and the People's Republic of Lugansk and expressed the will to develop the state-to-state relations with those countries in the idea of independence, peace and friendship."

Earlier Wednesday, the separatists' representation in Moscow issued a photo on Telegram showing its envoy Olga Makeyeva receiving what she described as a letter of recognition from North Korea's ambassador, Sin Hong-chol.

Donetsk and neighbouring Lugansk lie in the Donbas coal region in eastern Ukraine.

The region has been partially controlled by pro-Russian forces since 2014, a move that followed Russia's annexation of the Ukrainian peninsula of Crimea.

The 2022 offensive has been defended by Russia in part as the need to protect the two separatist entities.

The Donetsk separatists inaugurated their "embassy" in Moscow on Tuesday and said then they were in talks with North Korea on possible recognition.

Separatist officials have long said they want their regions to eventually join Russia.