MOSCOW, Jan 17, 2025 (BSS/AFP) - Russia and Iran will sign a "comprehensive strategic partnership" treaty on Friday during a visit to Moscow by Iranian President Masoud Pezeshkian, cementing ties between two of the world's most heavily sanctioned countries.

The agreement comes just three days before Iran-hawk Donald Trump enters the White House and as Moscow and Tehran seek to formalise their close relationship after years of deepening cooperation.

Iran has supplied Russia with self-detonating "Shahed" drones that Moscow fires on Ukraine in nightly barrages, according to Ukrainian and Western officials, while both nations have ramped up trade amid Western sanctions.

The new treaty will strengthen Tehran and Moscow's "military-political and trade-economic" relations, the Kremlin said on Wednesday, without providing further detail.

Tehran has given little information about Friday's pact, but ruled out a mutual defence clause like the one included in Russia's treaty with North Korea last year, Russian state media reported, citing Tehran's top diplomat Abbas Araghchi.

The two sides had been working on a new treaty for years, with their current relationship governed by a 2001 agreement that they have renewed periodically.

- 'Global hegemony' -

Russia says its upcoming pact with Iran and the already-signed treaty with Pyongyang are "not directed against any country".

"The treaty ... is constructive in nature and is aimed at strengthening the capabilities of Russia, Iran, and our friends in various parts of the world," Russian foreign minister Sergei Lavrov said Tuesday.

It is set to be valid for 20 years, Russia's TASS news agency reported on Tuesday, citing the Iranian ambassador to Russia Kazem Jalali.

Russian President Vladimir Putin has made building ties with Iran, China and North Korea a cornerstone of his foreign policy as he seeks to challenge what he calls as US-led "global hegemony".

Both Russia and Iran are under heavy Western sanctions that include restrictions on their vital energy industries.

At a summit of the BRICS group in Kazan last year, Putin told Pezeshkian he valued "truly friendly and constructive ties" between Russia and Iran.

Pezeshkian's visit to Russia comes just days before Trump returns to power.

The US president-elect, who has made repeated military threats against Iran, is seeking a rapid end to the conflicts in Ukraine and the Middle East.

The agreement comes a month after a rebel offensive overthrew Syrian leader Bashar al-Assad -- who was heavily supported by both Moscow and Tehran -- and as Israel and Iran's ally Hamas gear up for a ceasefire in Gaza.