The Russian foreign minister was welcomed by Iranian Ambassador to Russia Kazem Jalali, and then Lavrov signed a book of condolences, Tass reported.
Lavrov also signed a book of condolences which is opened on May 22 and will be available to the public in the next two days, the Russian news agency added.
On Wednesday, the third day of the national mourning declared in Iran after the tragic helicopter crash, dignitaries from dozens of countries, including Russia took part in a funeral ceremony held on Tehran.
MNA