There are reports that Russian President Vladimir Putin will visit Iran next month.
Russian and Iranian media say Putin will meet Iran's newly elected president for talks on the country's nuclear program.
On July 24, the Russian daily "Kommersant" quoted a source close to the Iranian Foreign Ministry as saying Putin would visit on August 12.
However, Iran's Mehr news agency said the Russian leader would arrive on August 16.
The inauguration of Hassan Rohani as the Islamic republic's president takes place on August 3.
Kremlin spokesman Dmitry Peskov has declined to confirm the reports.
Putin last visited Iran in 2007 to participate in a summit of the countries bordering the Caspian Sea.
A number of Western countries believe Iran wants to build a nuclear weapon, but Tehran says its nuclear program is for peaceful purposes.
Based on reporting by Reuters, AFP, and Interfax