Weeks after Hanoi's protest against Chinese ships sailing in its waters, the US aircraft carrier Ronald Reagan arrived in the central Vietnamese city of Da Nang on Sunday, AFP reports.

A Chinese research vessel, several coast guard ships and fishing boats have been sailing in Vietnam's exclusive economic zone in the South China Sea for several weeks, prompting protests from the Vietnamese Foreign Ministry.

The US aircraft carrier's visit follows the arrival of Indian Navy ships in Da Nang last month and the arrival of Japan's largest warship in Cam Ranh earlier this week.

Vietnamese Foreign Ministry Spokesperson Pham Thu Hang said that the port calls were "ordinary friendship exchange for peace, stability, and cooperation and development in the region and the world".