WASHINGTON, July 17 -- The U.S. Federal Aviation Administration (FAA) on Thursday issued a notice prohibiting American airliners from flying to the airspace over eastern Ukraine.

FAA said the restricted area includes the entire Simferopol and Dnepropetrovsk flight information regions.

"This action expands a prohibition of U.S. flight operations issued by the FAA in April, over the Crimean region of Ukraine and adjacent areas of the Black Sea and the Sea of Azov," FAA said in the notice.

No scheduled U.S. airlines are currently flying routes through this airspace, it said.

A Malaysian flight with 283 passengers and 15 crew members on board crashed Thursday in Ukraine near the Russian border. U.S. officials told media that they concluded the plane was shot down by missiles.