Iran's Foreign Ministry spokesman said the Russian use of Hamedan air base for conducting airstrikes against militants in Syria has come to an end.
Speaking in his first press briefing in Tehran on Monday, Bahram Qasemi said the two countries had agreed about sharing capacities as part of counter-terrorism collaboration on a "temporary" basis.
Last Tuesday, Russia's Ministry of Defense announced that its fighter bombers had been deployed to hit targets in Syria from a base in Iran.
Long-range Russian Tupolev-22M3 bombers and Sukhoi-34 fighter bombers used the Nojeh Air Base, near the western city of Hamedan, for several days to launch airstrikes against the self-styled Islamic State terrorist group and other militants fighting to topple the Syrian government.
Qasemi did not explain why the cooperation has ended, but said the two countries had agreed to publicize it at a later time.
"Nothing was supposed to be hidden, but due to the sensitivity of the operation, there was an agreement to publicize the operation after it was carried out," he said.
The announcement led to concerns voiced by some lawmakers that allowing the use of Iranian bases to another country may be in violation of the Iranian Constitution, according to which no foreign country can have a military base inside Iran.
Defense Minister Hossein Dehqan dismissed that criticism in a press conference on Saturday, saying, "We didn't give Russia a military base ... We facilitated the implementation of an anti-IS operation in Syria, on which we had agreed before."
The defense minister said Russians could use the Hamedan air base "as long as needed".
However, on Monday night, Dehqan in a talk with state TV criticized Moscow for broadcasting the move, describing it as an attempt for showing off.
"Russians seek to show they are a superpower ... and are influential on the Syrian battlefields, so they can negotiate with the US and ensure their share in Syria's political future," he said.
The Iranian deployment allowed the Russian air force to cut flight times and increase bombing payloads.
Syria has been gripped by foreign-backed militancy since March 2011 with various terrorist groups, including IS, currently controlling parts of it. Both Iran and Russia back the Syrian government against its opponents.
