Vladimir Putin will meet UN chief Antonio Guterres for the first time in over two years on Thursday, as the Russian president faces calls from his BRICS allies to end the conflict in Ukraine.
The meeting takes place on the final day of the BRICS summit in the Russian city of Kazan, a forum Moscow hopes will help forge a united front of emerging economies against the West.
The pair are expected to discuss the conflict in Ukraine as well as the escalating crisis in the Middle East, according to the Kremlin.
Guterres has repeatedly criticised Moscow's military offensive against Ukraine, saying it sets a "dangerous precedent" for the world.
The two men last saw each other in the first weeks of the offensive when Guterres travelled to Moscow during Russia's siege of Mariupol in south Ukraine.
Guterres has since been involved in peace efforts between the two sides, helping to broker a deal that allowed Kyiv to safely export grain from its ports in 2022.
There has been little direct diplomatic contact between the two countries since.
Ukraine has strongly criticised the UN chief's decision to meet Putin.
Putin has demanded Ukraine surrender territory in its south and east as a precondition for a ceasefire, a position Kyiv has called "absurd".
The Putin-Guterres talks come as Moscow's troops advance in Ukraine's eastern Donetsk region, edging closer to the key supply hub of Pokrovsk.
The United States has warned that thousands of North Korean soldiers have been sent to Russia, in what the West and Kyiv fear could develop into a major troop deployment to support Moscow.
The United Nations has said that Guterres plans to meet Putin in Kazan, where he will also deliver a speech.
UN spokesman Farhan Haq said Guterres would use the meeting to "reaffirm his well-known positions on the war in Ukraine".
Haq said the UN chief is on standby to offer mediation, but is waiting for when "the conditions are right".
"Obviously he stands ready, when the parties are willing, to offer his services. He will continue to monitor and see when the situation is right."
Ukraine has slammed Guterres's Russia visit, with Kyiv's foreign ministry blasting him for planning to meet the "criminal Putin".
Guterres has criticised Moscow's annexation of Ukrainian territory, saying it has "no place in the modern world".
He has visited areas where the Russian army has been accused of atrocities in Ukraine, and repeatedly called for a "just peace".
The meeting comes a day after the United States said it believed "thousands" of North Korean soldiers were being trained in Russia.
"We don't know what their mission will be or if they'll go on to fight in Ukraine," a senior US official said.
Putin -- who signed a mutual defence pact with North Korea on a trip to the reclusive state in June -- has not yet commented on the reports.
Russia on Wednesday said to "ask Pyongyang" about troop movements, refusing to confirm or deny the allegations.
Several world leaders called for an end to the Ukraine conflict at the BRICS summit.
Indian Prime Minister Narendra Modi -- who has also tried to mediate between Moscow and Kyiv -- said on Tuesday he wanted the conflict to be resolved "peacefully".
"We totally support efforts to quickly restore peace and stability," he said.
New Delhi has walked a delicate tightrope since Moscow launched its offensive, pledging humanitarian support for Kyiv while avoiding explicit condemnation of Moscow's actions.
South African President Cyril Ramaphosa has also urged an end to the conflict.
On Wednesday night, Saudi foreign minister Prince Faisal bin Farhan also arrived in Kazan "as a state invited to join the (BRICS) group", his ministry said on social media platform X.
