An official at Egypt's Suez Canal says a US aircraft carrier and a destroyer have crossed the waterway from the Mediterranean Sea to the Red Sea.
The official says the US warships crossed on Friday after 14 hours of heightened security along the canal that included closing all roads near the canal and having Egyptian military helicopters provide air support.
The official said the aircraft carrier was the USS Nimitz, based in the US state of Washington. He did not identify the destroyer and spoke on condition of anonymity because he was not authorised to brief reporters.
The US is bringing the aircraft carrier back to the US from the Arabian Gulf region, said the US Defense Department, after keeping two of the warships there for months as the Obama administration considered a military strike against the Syrian government.
In September, the US Navy increased its presence in the Middle East to keep watch over Syria amid threats to strike the country over a chemical weapons attack there.
The decision to bring back the USS Nimitz underscores the shift from a pointed military threat against the Syrian government to a broader diplomatic approach. It comes as international experts work to meet a mid-2014 deadline to eliminate Syria's chemical weapons program.
According to officials, the USS Nimitz moved through the Suez Canal and into the Red Sea, and is expected to be back at its home port on the west coast of the US before Christmas. The Navy destroyer, the USS Graveley, was also returning home.
The US sharply increased its naval presence in the region after a deadly August 21 chemical weapon attack on rebel-held suburbs of Damascus. Washington and its allies said the Syrian government was responsible for the attack.
The US spread cruisers and destroyers across the eastern Mediterranean, waiting for the command to launch missiles into Syria. But after threatening military action, President Barack Obama abruptly announced on August 31 that he would go to Congress for approval of a strike.
After vocal opposition in Congress and from the US public, increased diplomatic efforts ultimately secured the right for experts to inspect chemical weapons sites in Syria as part of a mission to destroy all facilities and machinery for mixing the chemicals into poison gas.
Syria is believed to possess around 1,000 metric tons of chemical weapons, including mustard gas and sarin.
The aircraft carrier USS Harry S Truman remains in the North Arabian Sea, and three US warships – the USS Stout and the USS Ramage, both destroyers, and the USS Monterey, a cruiser – are in the eastern Mediterranean.