HONG KONG — The United States plans to send an aircraft carrier to dock in Vietnam, officials from both nations said on Thursday, a telling sign of Washington’s warming relations with a country that was once battered by American bombs.

The proposed visit to the port of Danang comes amid heightened tensions over China’s territorial claims in the South China Sea, including to islands claimed by Vietnam. The Defense Ministry of Vietnam announced the port call while the American defense secretary, Jim Mattis, was in Hanoi.

Danang was where the first conventional American combat unit was deployed in the Vietnam War, landing on a beach there in 1965. Hundreds of thousands more troops were to follow.

The arrival of the aircraft carrier, planned for March, would represent the largest presence of United States forces in Vietnam since the war ended in 1975. Smaller Navy ships have visited Vietnam as the two countries’ relationship has improved.