Iranian Supreme Leader Ali Khamenei urged Belarusian President Alexander Lukashenko to confront US sanctions, noting that countries subject to Western sanctions must counter the scheme through cooperation and by setting up a joint assembly.
The two countries signed a roadmap to boost political, economic, and cultural cooperation.
Lukashenko arrived in Tehran on Sunday for a two-day visit and was officially received by President Ebrahim Raisi on Monday. The visit comes as the two countries mark 30 years of official diplomatic relations.
Khamenei called for employing the two countries' will to implement cooperation agreements and promote their level of relations.
Raisi hailed three decades of close ties with Belarus after talks with his counterpart.
"Thirty years after the start of relations... the two countries have the will to strengthen cooperation," Raisi said, praising their "common strategic vision."
For his part, Lukashenko praised "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 program, which has sparked tough international sanctions against the country.
"We could be very helpful to each other if we put our efforts together," added Lukashenko.
The two presidents did not mention the Ukraine war in their statements.
Lukashenko is a close ally of Russian President Vladimir Putin, while Tehran maintains close ties with Russia while at the same time asserting it maintains a neutral diplomatic stance in the Ukraine war.
However, Washington recently warned of the "dangerous" increase in military cooperation between Russia and Iran, accusing Tehran of providing Moscow with drones to use in Ukraine, which Tehran denies.
Iran recently announced that it finalized a contract with Russia to purchase Sukhoi Su-35 fighter jets.
Lukashenko recently paid a three-day visit to China, during which he said he fully supports Beijing's proposals to stop the war.
Belarus, neighboring Ukraine, did not send soldiers to fight alongside the Russian army, but its territory served as a rear base for Moscow's troops.