The presidents of Iran and Belarus hailed their close ties in talks in Tehran Monday at a time both countries are sharply at odds with Western powers, including over Russia's war in Ukraine.

Ex-Soviet state Belarus serves as a rear base for Russian troops, and Iran is accused of supplying Moscow with armed drones for use in the invasion -- a charge it denies while proclaiming its neutrality in the conflict.

Iranian President Ebrahim Raisi hailed three decades of close ties with Belarus after talks with his counterpart Alexander Lukashenko, who arrived late Sunday for a two-day visit.

"Thirty years after the start of relations ... the two countries have the will to strengthen cooperation", Raisi said, praising their "common strategic vision".

Lukashenko said he had observed "with great respect the perseverance with which the (Iranian) people resist external pressures, attempts to impose the will of others on them".

"And I see that, despite everything, you are developing modern technologies and nuclear energy," he added about Iran's contested nuclear programme which has sparked tough international sanctions against the country.

"We could be very helpful to each other if we really put our efforts together," added Lukashenko.

The two presidents, who did not mention the Ukraine war in their statements, signed a roadmap to boost political, economic and cultural cooperation.

Lukashenko is an ally of Russian President Vladimir Putin, while Tehran also maintains close ties with Russia even as it has stressed a neutral diplomatic stance in the Ukraine war.

Washington has accused Iran of supplying suicide drones to Russia, and expressed alarm over a "dangerous" escalation in military cooperation between Tehran and Moscow.

Iran -- which has denied supplying drones to Russia specifically for use in Ukraine -- has said it has finalised a contract to buy Russian Sukhoi Su-35 fighter jets.

Lukashenko recently made a three-day visit to China, where he voiced support for Beijing's proposal to mediate in efforts to end the Ukraine war.

Belarus, a neighbour of Ukraine, has not sent soldiers to fight alongside the Russian army, but its territory has served as a rear base for troops from Moscow.

Lukashenko's visit to Iran was the third ever by a Belarusian president and the first in 17 years, according to state-run news agency Belta.