WASHINGTON (Reuters) - U.S. Defense Secretary Ash Carter said on Thursday he would support lifting restrictions on the sale of weapons to Vietnam, in the latest sign of thawing ties between former enemies whose focus has shifted in recent years to China’s military buildup. When asked by Senator John McCain, chairman of the Senate Armed Services Committee and a former prisoner of war in Vietnam, if he would support lifting the restrictions, Carter said at a hearing: “We’ve discussed this in the past and I appreciate your leadership in that regard, chairman, and yes.” Carter did not elaborate, although his comments come ahead of a planned visit to Vietnam by U.S. President Barack Obama late next month. The United States partially lifted a long-time ban on lethal weapons sales to Vietnam in October 2014, nearly 40 years after the end of the Vietnam War, to help the country patrol and defend itself in the South China Sea in the face of growing naval challenges from China. At the time, U.S. officials said future sales could include airborne systems.  Carter pledged on a visit to Vietnam last year to provide it $18 million to help its coast guard buy U.S. patrol boats. But the United States has said that fully lifting the embargo will depend on improved human rights conditions in Vietnam.  “There are a number of factors that we must consider with regard to lifting the ban, including progress on human rights,” the State Department’s top human rights official, Tom Malinowski, said on Tuesday after an annual human rights dialogue with Vietnam on Monday. 
Pentagon chief would back lifting restrictions on U.S. arms to Vietnam