The aircraft carrier USS Kitty Hawk on Monday again left port, possibly to participate in a U.S.-led multinational effort to respond to the terrorist attacks in the United States last month.

It had just returned Sunday after being out to sea for nine days.

"The Kitty Hawk departed Yokosuka on Monday to support tasking as assigned by the National Command Authority in response to Operation Enduring Freedom," the U.S. military headquarters in Japan said.

The 81,123-ton vessel may be heading to the Indian Ocean to prepare for the expected strikes against Afghanistan. The Japan Coast Guard deployed 24 patrol boats, three helicopters and special units to escort the aircraft carrier as it left the port.