WASHINGTON - Two US Navy ships patrolling in the Middle East moved closer to Egypt's Red Sea coast in recent days, the top Marine Corps general said on Thursday, in what appeared to be a precautionary move after the military overthrow of President Mohamed Morsi.The United States often sends Navy vessels close to countries in turmoil in case it needs to protect or evacuate US citizens or take part in humanitarian assistance. Their presence does not necessarily mean the United States is preparing to carry out military action. "Egypt is (in) a crisis right now," Marine Corps Commandant General James Amos told the Center for Strategic and International Studies think tank. "When that happens, what we owe the senior leadership of our nation are some options," Amos said. He did not say what the options were.US Navy and Marine Corp officials said the two ships, part of a three-ship amphibious readiness group, had been in the region since May, patrolling the Red Sea, Horn of Africa, the Gulf and the Arabian Sea, and that there were no new orders to prepare for a possible conflict in Egypt.Washington has walked a careful line, neither welcoming Morsi's removal last week nor denouncing it as a "coup." US defense officials on Wednesday said they still planned to send four F-16 fighter jets to the Egyptian government as planned in coming weeks.Amos said the USS San Antonio, an amphibious transport dock, and the USS Kearsarge, an amphibious assault ship, had moved further north in the Red Sea two or three nights ago to better respond if needed.US Marine Corps officials said moving amphibious ships closer to shore would enable easier movement of helicopters and other equipment, if it were needed."Why? Because we don't know what's going to happen," he said.Navy officials said the third ship in the group, the USS Carter Hall, remained off the coast of Bahrain in the Gulf.