A Russian delegation arrived in Tehran for a visit that includes a meeting with Iranian President Masoud Pezeshkian, Russian state news agency TASS reported on Monday, as the two countries prepare to sign a comprehensive cooperation agreement.

Iran and Russia have been working on setting a date to complete an agreement, Iran's Foreign Ministry Spokesperson Esmaeil Baghaei said on Monday, adding that the deal is set to be signed during a bilateral visit in January.

Russia has cultivated closer ties with Iran and other countries hostile towards the United States, such as North Korea, since the start of the Ukraine war.

The country's Foreign Minister Sergei Lavrov said in October that Moscow and Tehran intended to sign a deal which would include closer defence cooperation.

The Russian delegation to Iran is headed by deputy prime ministers Alexei Overchuk and Vitaly Savelev, according to Russia's Interfax news agency.

"The parties are expected to discuss the joint work of Iran and the countries of the Eurasian Economic Union (EAEU) within the framework of a full-fledged agreement on a free trade zone," Interfax said on Monday.

The United States accused Tehran in September of delivering close-range ballistic missiles to Russia for use against Ukraine, and imposed sanctions on ships and companies it said were involved in delivering Iranian weapons. Tehran denies providing Moscow with the missiles.