The visit of the USS Ronald Reagan is only the third for a U.S. aircraft carrier since the end of the Vietnam War.
The USS Theodore Roosevelt stopped in Vietnam in 2020 to mark 25 years since the Vietnam War ended in 1975.
This year Washington is seeking to upgrade its formal ties with Vietnam, amid Hanoi's frequent disputes with Beijing over boundaries in the South China Sea.
China claims the waters almost in their entirety, including the exclusive economic zones of Vietnam and other countries in the region.
On Wednesday, the Chinese aircraft carrier Shandong and a group of escorting vessels sailed south through the sensitive Taiwan Strait, Taiwan's defence ministry said.
Persons:
Ronald Reagan, Theodore Roosevelt, Francesco Guarascio
Organizations:
U.S, aircraft, Thomson
Locations:
HANOI, Central Vietnam's, Danang, U.S, Beijing, South China, Vietnam, Washington, China, Shandong, Taiwan