Updated

Vietnam kicked off a weeklong naval exchange Monday with the U.S. Navy, with the former battlefield enemies cooperating amid percolating tensions in the South China Sea with Beijing.

Three ships from the U.S. 7th Fleet visited Danang during the five-day event that began Monday. No live-fire drills were planned, but the two sides were expected to practice salvage and disaster training as they have done in recent years.

"This exchange enhances collective cooperation, and promotes understanding between our Navies," Rear Adm. Tom Carney said in a statement Monday.

Washington and Hanoi normalized diplomatic relations in 1995, more than two decades after the U.S. withdrew its troops from the Vietnam War. The U.S. is a now key trading partner for Vietnam and the former enemies have developed closer military ties.

Vietnam, China, the Philippines and other nations have competing claims to islands in the South China Sea, which is believed rich in oil and gas deposits. Many view the sea as a potential flash point of armed conflict.

Tensions have flared this month near a shoal north of the disputed Spratly Islands where two Chinese maritime surveillance ships blocked a Philippine warship from arresting Chinese fishermen on April 10. Chinese and Philippine vessels continued to face off at the shoal on Monday, each waiting for the other to pull out.

Earlier this month, five Vietnamese Buddhist monks traveled to the Spratlys to teach Buddhism and defend their nation's territorial claim.

Tensions between Vietnam and China hit a low point last summer after Hanoi accused Beijing of interfering with its maritime oil exploration activities. Beijing denied the charge.

The last major clash in the sea involved China and Vietnam and left more than 70 Vietnamese sailors dead in 1988.

Beijing has named the South China Sea one of its "core interests," meaning it could potentially go to war to protect it.

The U.S. has said it has a national interest in ensuring freedom of navigation in the sea, and analysts say Washington is expanding its military presence in Asia to counter China's rising influence.