Tuesday's vote comes with high tensions between Iran and the West and as Russia pushes a rapprochement with Washington despite its offensive on Ukraine.

Amid deepening military cooperation over the last three years, Iran has been accused by Kyiv and the West of supplying weapons, including self-detonating "Shahed" drones to Russia for its campaign against Ukraine.

In the treaty, the sides agreed to help each other counter common "security threats", but it stops short of a mutual defence pact like the one signed between Russia and North Korea last year.

"The signing of the treaty does not mean the establishment of a military alliance with Iran or mutual military assistance," Russian Deputy Foreign Minister Andrei Rudenko said in an address to the State Duma.

Instead the treaty states that if either side is subjected to aggression, the other will not provide "assistance to the aggressor".

The comprehensive strategic partnership deal was signed by Presidents Vladimir Putin and Masoud Pezeshkian in January, with votes in Moscow's rubber-stamp parliament necessary before it can come into force.

Putin at the time called it a "breakthrough document", while Pezeshkian said it would "open a new chapter in relations between Iran and Russia in all fields".

Moscow has urged caution over escalating tensions between the Iran and the United States after President Donald Trump appeared to threaten to bomb Iran if it did not come to the table for talks on limiting its nuclear programme.

Trump said direct talks with Iran would take place this Saturday on the issue.

Russia has forged closer ties with several of the West's adversaries -- including North Korea and China -- since launching its offensive on Ukraine.

Russia signed a strategic partnership treaty last year with Pyongyang that outlines possible mutual military assistance in case of an attack and cooperation in the face of Western sanctions.