President Putin landed in Tehran at Friday noon (at 1:45 pm local time) and was officially received by Iranian Energy Minister Reza Ardakanian, Tasnim news agency reported on September 7.
Iran's Minister of Industry, Mine and Trade Mohammad Shariatmadari also welcomed President Erdogan in the capital at 1 pm (local time).
Iranian President Hassan Rouhani and his Turkish counterpart are slated to meet ahead of the summit.
In April, the presidents of Iran, Russia and Turkey - the three guarantor states of de-escalation zones in Syria - held a meeting in Ankara to discuss ways for peaceful settlement of the crisis in Syria.
The three countries have so far held several rounds of peace talks in Kazakhstan’s Astana and elsewhere to help end the conflict in Syria. The fourth round of those talks in May 2017 produced a memorandum of understanding on de-escalation zones in Syria, sharply reducing fighting in the country.
Diplomatic efforts to end fighting in Syria gained momentum in 2017 with the announcement of a ceasefire in the Arab country in early January.
According to a report by the Syrian Center for Policy Research, the conflict has claimed the lives of over 470,000 people, injured 1.9 million others, and displaced nearly half of the country’s pre-war population of about 23 million within or beyond its borders.