Moscow - US airlines are still able to fly in Russian airspace, the transport ministry assured on Wednesday despite a transit agreement between Washington and Moscow expiring shortly.
"The Transport Minister of the Russian Federation confirms that flights of American companies over Russian territory are still authorised according to the existing scheme before new negotiations," transport ministry spokesman Timur Khikmatov told AFP.
"This week we sent our American colleagues a proposal to negotiate on this issue. A date for the negotiations has not been agreed yet. We are waiting for an answer from our American colleagues," he added.
Russian Transport Minister Maxim Sokolov was reporting as saying that Moscow was considering retaliatory measures against Washington in the sector as a response to recent US sanctions.
"We are considering various answers that our country could give to the introduction of sanctions that are unlawful from our point of view. While it is too early to speak about it, a response will be prepared, approved and adopted in its own time," Sokolov was cited as saying by news agencies.
Every day, dozens of American flights cross Russian skies on their shortest and most lucrative routes to Asia but their permission to do so is due to run out at 19:59 (23:59 GMT).
US State Department spokeswoman Heather Nauert said on Tuesday that the US ambassador to Moscow, Jon Huntsman, was in last-minute discussions with Russian officials to facilitate a breakthrough in talks with airlines.
Russian civil aviation officials had been due to attend discussions hosted by the State Department in Washington, but cancelled. The airlines sent representatives to the talks.
Nauert said the Russians had not indicated why they had backed out of the meetings.
But the decision came after Saturday's US-led air strikes on Syria angered Moscow, which has previously attempted to use air routes as diplomatic bargaining chips.