A Navy helicopter crashed in the Red Sea on Sunday while conducing military support operations for U.S. warships stationed in the region.
The status of the five crew members aboard the MH-60 Knighthawk helicopter is still under investigation, according to a statement by the Navy's Fifth Fleet in Bahrain.
Three crew members are accounted for and stable, the Navy said. Search efforts continue for two remaining personnel.
The helicopter was flying support missions for the Navy destroyer USS William P. Lawrence when the incident occurred, fleet officials say.
"The crash was not due to any sort of hostile activity" in the region, according to the Navy.
Pentagon officials last week extended the deployment of the Nimitz strike group, as well the Navy destroyer USS Barry, in the coastal waters near Syria.
The extensions are part of the Defense Department's efforts to "maintain a strong military posture" in the region, according to Pentagon press secretary George Little.
American naval forces in the Mediterranean and Red Sea "stand ready for any military action" ordered by the White House on Syria, he said during a Sept. 19 press briefing.
President Obama is scheduled to address a tentative disarmament deal for Syria at the United Nations this week.
On Thursday, Secretary of State John Kerry demanded Assad hand over all of the country's stockpiles to international control when the U.N. Security Council meets in New York.
Assad submitted his assessment of the country's chemical weapons stockpiles to United Nations investigators on Friday, clearing the first hurdle toward an eventual disarmament deal.
--This report was updated at 4:26 p.m.