According to reports, North Korea has promised to support Russia in the conflict with Ukraine "until it achieves victory." 

Vladimir Putin's forces will "achieve a great victory in their sacred struggle to protect the sovereign rights and security interests," according to Foreign Minister Choe Son Hui. 

The Guardian quotes Sergei Lavrov, her opposite number, as saying that the Kremlin is "deeply grateful to our Korean friends for a principled position." 

The news comes after a warning from the British defence secretary of strengthened ties between Moscow and Pyongyang. 

John Healey said on Friday evening that UK Defence Intelligence had confirmed 10,000 North Korean soldiers had arrived in Russia. 

The Ministry of Defence (MoD) said it was “almost certain some have already deployed to the Kursk region” - where Ukraine has been planning a counterattack. 

Mr Healey said: “This growing alliance of aggression shows why we must continue to stand steadfast behind Ukraine’s fight for freedom.”

Russian president Vladimir Putin said on Thursday that it was Moscow's business how to implement a partnership treaty with Pyongyang. 

Mr Putin did not deny that North Korean troops were in Russia. "This is our business," he said.

Ukrainian president Volodymyr Zelensky has called for the country’s allies to help. 

In a message on social media platform Telegram he said: “The first thousands of soldiers from North Korea are near the Ukrainian border. 

“Ukrainians will be forced to defend themselves against them and the world will watch again.”

He added in his evening address on Friday that Ukraine needs the permission of its allies to fire long range missiles at its targets. 

This week Ukraine has started using AI-guided drones to hit Russian targets.