WASHINGTON (Reuters) - The United States hopes to reach agreement for another aircraft carrier visit to Vietnam this year and for such port stops to become a regular feature of the increasingly close relationship between the former Vietnam War enemies, a senior U.S. defense official said on Wednesday.

The USS Carl Vinson stopped in Vietnam in March last year in the first such visit since the end of the Vietnam War in 1975, underscoring the growing strategic ties between the former foes at a time when China’s regional influence is rising.

“We had our first aircraft carrier visit to Vietnam since the end of the Vietnam War and we very much hope we can reach agreement with our colleagues in Vietnam for a second aircraft carrier visit this year,” Randall Schriver, the assistant secretary of defense for the Indo-Pacific region, told a Washington think tank.

“We are discussing it with Vietnam right now. Our hope is that this can be a regular feature of the relationship. It would be a sign of a mature and a strategic relationship,” Schriver told the Center for Strategic and International Studies.

Schriver also said he hoped the United States would be able to make a second coast guard cutter available to Vietnam to help with maritime security work.

On Monday, the United States delivered six patrol boats worth $12 million to Vietnam’s Coast Guard.

U.S. President Donald Trump used a meeting with Vietnamese officials in February to pitch arms exports from the United States.

Decades after the U.S. war in Vietnam, ties between the two countries are increasingly seen through shared concern over China’s aggressive behavior in the South China Sea, through which more than $3 trillion in cargo passes every year.

U.S. carriers frequently cross the South China Sea in a rising pattern of naval deployments, and are now routinely shadowed by Chinese naval vessels, naval officers in the region say.

Vietnam has emerged as the most vocal opponent of China’s territorial claims and has been buying U.S. military hardware, such as an armed Hamilton-class Coast Guard cutter.