Russia and Tehran, who are both subject to fierce Western sanctions, have developed an increasingly close relationship in recent years.

Tehran's ambassador Kazem Jalali wrote on X that Araghchi would meet Putin in Russia's second biggest city.

"Continuing the diplomatic jihad to advance the country's interests and amidst external threats, the Minister of Foreign Affairs of the Islamic Republic of Iran will meet with the President of Russia during his visit to St. Petersburg," he wrote.

Iran's ISNA news agency earlier quoted Jalali as saying "Foreign Minister Abbas Araghchi will meet with Russian President Vladimir Putin during his visit to Moscow," without providing a location for the talks.

The meeting would take place on Monday, Jalali said according to ISNA, adding that Araghchi would "consult Russian officials regarding the latest status of the negotiations, ceasefire, and surrounding developments".

Russia's foreign ministry confirmed on Sunday that Araghchi would travel to Moscow "with the aim of holding talks", the RIA Novosti news agency reported.

The Iranian foreign ministry said in a statement that Araghchi had already left Islamabad for Russia on Sunday.

His stopover in the Pakistani capital on the way to Russia was his second visit there in less than 24 hours, having also travelled to Oman, as mediators pushed to keep peace talks with the United States alive in a bid to end the war that began on February 28.

There has been no second round of direct talks between Washington and Tehran, despite a ceasefire in the US-Israeli war with Iran beginning more than two weeks ago.