US Defense Secretary Leon Panetta began a visit to Vietnam in Cam Ranh Bay Sunday, becoming the highest ranking US official to visit the former US military base since the war years. Panetta visited the navy supply ship USNS Byrd which is berthed in the bay undergoing maintenance, according to a report of DPA. Panetta then travelled to Hanoi for meetings at the Ministry of Defence and Prime Minister Nguyen Tan Dung. Talks are expected to focus on defence cooperation, maritime security, humanitarian assistance and disaster relief. The visit is part of an agreement the two countries signed in 2003 to exchange defence ministers every three years. This year's visit follows Panetta's weekend announcement that the US navy will deploy 60 per cent of its forces to the Pacific by 2020, up from the current 50 per cent.