FILE PHOTO: A Delta jetliner (foreground) is de-iced while an American Airlines plane (rear) takes off at Reagan National Airport in Washington January 3, 2014. REUTERS/Gary Cameron

WASHINGTON (Reuters) - Russia agreed to extend by six months overflight approvals for U.S. airlines, the U.S. State Department said on Tuesday, hours before an agreement on overflights was due to expire.

The agreement that allows U.S. carriers to fly over Russia was to expire at 7:59 p.m. (2359 GMT).

The State Department said the extension was for operations on three routes through Oct. 28, 2018. It did not specify the routes.

Additionally, the Russian Ministry of Transport extended approvals for all cargo flights from Asia to Europe through April 20 but proposed an alternative route after that date, which was being discussed, the State Department said.

“We are also working to schedule discussions with Russian civil aviation officials to discuss this and other civil aviation matters,” the State Department said. “Our goal remains to provide as many benefits as possible for U.S. carriers.”

Earlier, State Department spokeswoman Heather Nauert told a daily briefing for reporters that the department had met with representatives from U.S. commercial and cargo carriers to discuss their concerns as the deadline loomed.

U.S. diplomats in Moscow were in touch with the Russian government, she said.

Russian civil aviation officials had canceled a meeting in Washington this week to discuss renewing the agreement, Nauert said.

Discussions on the overflights unfolded amid tensions between Moscow and Washington after the United States, France and Britain launched missile strikes in Syria on Saturday aimed at curbing that country’s chemical weapons programs. Russia is a staunch ally of Syrian President Bashar al-Assad.