Iran's Foreign Minister Mohammad Javad Zarif will travel to Russia next week for a meeting of the countries that border the Caspian Sea, the official IRNA news agency reported.
"Mr Zarif will arrive in Russia on Tuesday,' for the gathering of the Caspian Sea littoral states, Iran's ambassador to Russia, Mehdi Sanaei, wrote on his Facebook page.
Since the formal dissolution of the Soviet Union, the nations that border the Caspian (Iran, Russia, Azerbaijan, Kazakhstan and Turkmenistan) have failed to agree on the sea's legal status.
Signup to our newsletter and follow us on Facebook and Twitter!
Sanaei also said Iranian President Hassan Rouhani would visit Russia in September for a meeting of the heads of the Caspian sea countries.
Iran and Russia are close allies. In Syria's civil war both nations have supported President Bashar al-Assad's regime against mainly Sunni rebels.
In January, Rouhani told Russian President Vladimir Putin that establishing long-term relations between the two countries "can serve the stability and security of the region".
Russia built Iran's sole nuclear power plant in Bushehr and the Islamic republic has signed a preliminary agreement that will see Moscow build two more atomic plants.
Russia is a member of the so-called P5+1 world powers -- along with the United States, China, France, Britain plus Germany -- which is conducting talks with Iran to seek a permanent agreement on Tehran's disputed nuclear programme.