The United States has warned Americans against flying on local airlines in Indonesia because of safety concerns raised by recent accidents.

The U.S. Embassy in Jakarta issued the warning Tuesday. The statement said the U.S. Federal Aviation Administration downgraded the country's safety rating from one to two due to serious concerns about oversight and operational systems.

An Indonesian airliner plunged into the sea in January, killing all 102 people on board. In March, another plane overshot a runway and burst into flames, leaving 21 dead.

Indonesia's Transportation Minister Hatta Radjasa defended the country's safety initiatives Tuesday during a lunch with the Jakarta Foreign Correspondents' Club. He said enforcement has been stepped up after the recent airplane disasters.

Some information for this report was provided by AFP, AP and Reuters.