US news outlet Axios reported on Saturday, citing three anonymous sources familiar with the matter, that Putin had "encouraged" Iran to accept a deal with the United States that would prevent the Islamic republic from enriching uranium.

The article "appears to be a new political defamation campaign aimed at exacerbating tensions around Iran's nuclear program", the Russian ministry of foreign affairs said on Sunday.

"Invariably and repeatedly, we have emphasised the necessity of resolving the crisis concerning Iran's nuclear program exclusively through political and diplomatic means, and expressed our willingness to help find mutually acceptable solutions," the statement read.

Tehran is suspected by Western countries and Israel of seeking to develop an atomic bomb, which it denies, defending its "non-negotiable" right to develop a civilian nuclear program.

Moscow has a cordial relationship with Iran's clerical leadership and provides crucial backing for Tehran but did not swing forcefully behind its partner even after the United States joined Israel's bombing campaign in June.

Publicly, Moscow has defended Tehran's right to use nuclear technology for civilian purposes but in recent months, Putin has also drawn closer to US President Donald Trump.

On June 13, Israel launched an unprecedented attack on Iran, triggering a 12-day war.

The conflict halted negotiations initiated in April between Tehran and Washington to frame Iran's nuclear program in exchange for lifting economic sanctions against Iran.

On June 22, the United States bombed the underground uranium enrichment site at Fordow, south of Tehran, and nuclear facilities in Isfahan and Natanz.

The exact extent of the damage is not known.