Vietnamese officials were invited aboard the nuclear-powered USS George Washington as it cruised off the coast of Vietnam Saturday. There were exhibitions of F18 warplanes taking off and landing, and a live-fire exercise by an accompanying destroyer.Vietnamese officials said they were "pleased" to accept help from one-time foe America, as a hedge against its giant neighbour China, with which it sometimes finds difficult to maintain good relations."This is part of a typical patrol that (the carrier task force) conducts throughout the area of operations," Seventh Fleet spokesman Anthony Falvo said in a phone interview with the Bloomberg news agency Saturday. "We regularly patrol the Asia Pacific, have done so for many years and will continue to do so."Captain Gregory Fenton of the USS George Washington said the mission is aimed at improving relations with Vietnam and ensuring the US has free passage through the disputed waters.The US Navy regularly patrols the Asia-Pacific region, conducting joint exercises with its allies and training in the strategic region. The trip by the George Washington off the coast of Vietnam is its third in as many years. A second aircraft carrier, the USS John C. Stennis, has also conducting operations in the western Pacific region recently, according to the US Pacific Fleet.The high-profile weekend cruise past Vietnam, however - with the press invited along with Vietnamese military and civilian security officers - escalated the so-called "pivot" by the United States away from Europe and towards Asia.US President Barack Obama announced the pivot two years ago, and said a 10-year project would place more troops and mobile forces in a wide Asian arc from Australia to Guam, and north to Japan.The United States has taken no side in the territorial disputes among China and its neighbours.But the cruise, and joint military operations with Malaysia, support for Vietnam and a port visit to the Philippines shows Asean support.Aboard the George Washington, Capt Fenton told newsmen, "It is our goal to see the region's nations figure out these tensions ... on their own, our role of that to date is to conduct freedom of navigation exercises within international waters."There was plenty of speculation about the George Washington's weekend cruise, and there will be more at mid-week when the aircraft carrier task force visits the Philippines, arguably the most involved nation in the South China Sea territorial dispute."China will take this (cruise) as another expression by the United States of its desire to maintain regional domination," said Denny Roy, a senior fellow at the East-West Center in Hawaii, according to a report by the Associated Press. "The US also wants to send a message to the region that it is here for the long haul ... and that it wants to back up international law."