This year's visit follows Panetta's weekend announcement that theUS navy will deploy 60 per cent of its forces to the Pacific by 2020, up from the current 50 per cent.
Panetta visited the navy supply ship USNS Byrd which is berthed inthe bay undergoing maintenance.
Panetta then travelled to Hanoi for meetings with the Ministry ofDefence and Prime Minister Nguyen Tan Dung.
Talks are expected to focus on defence cooperation, maritimesecurity, humanitarian assistance and disaster relief. The visit ispart of an agreement the two countries signed in 2003 to exchangedefence ministers every three years.