Vladimir Putin and his Chinese counterpart Xi Jinping are set to strengthen strategic co-operation between their two countries. China's President will visit Russia between May 7 -11, where he is expected to attend the Victory Day Celebrations commemorating the 80th anniversary of the defeat of Nazi Germany.

The two leaders will sign a "series of deals" designed to cement ties between Russia and China. A statement from the Kremlin said: “The bilateral talks to be held during the visit will focus on the core aspects of further advancement of Russia-China relations of comprehensive partnership and strategic cooperation, as well as pressing matters on the international and regional agendas.”

It added: “The two leaders are to sign a number of bilateral inter-governmental and inter-departmental documents.”

Xi has previously declared a "no limits" friendship with Russia, which he reaffirmed after a phone call with the Kremlin boss in February on the third anniversary of Putin's full-scale invasion of Ukraine.

Following the conversation, Xi said: "China-Russia relations have strong internal driving force and unique strategic value, and are not aimed at, nor are they influenced by, any third party.

"The development strategies and foreign policies of China and Russia are long-term."

The Chinese leader added that the two countries "are good neighbours that cannot be moved apart".

The West has accused China of supplying weapons components to Moscow, a charge strenuously denied by Beijing.

China has stopped short of formally supporting Russia in the war and has warned Putin against the use of nuclear weapons.

However, there is growing evidence that Chinese mercenaries have signed up to fight with Putin's army in Ukraine.

Last month, Volodymyr Zelensky said two Chinese citizens were captured fighting for Russia in eastern Ukraine.

The Ukrainian president claimed his forces had fought with six Chinese soldiers in Donetsk and that there were “many more” in the Russian ranks.

A Ukrainian intelligence officer told the Express: "There have been reports of Chinese volunteers in Russian service beginning back in 2022.

"It seems to me it’s not a massive government campaign but private volunteers.

"There are Chinese military attachés with the Russians for sure but they tend to have a low profile."