The U.S. military said Tuesday it is suspending flights by HH-60 helicopters at Japan's request until the cause of a crash in Okinawa has been determined.

After attending the ceremony to mark the 68th anniversary of the U.S. atomic bombing of Hiroshima, Prime Minister Shinzo Abe said safety should not be compromised.

"It is important that the safety of local people comes first. We would like to ask the U.S. side to give utmost consideration to safety," he said during a news conference in Hiroshima.