US Defense Secretary Pete Hegseth landed Sunday in Vietnam's capital Hanoi, where he is expected to meet his Vietnamese counterpart Phan Van Giang.

It comes as Hegseth said on Sunday that Washington and Beijing would establish military-to-military communications channels, adding that bilateral ties between the countries have “never been better.”

His remarks posted on X came hours after he urged Southeast Asian nations to stand firm and strengthen their maritime forces to counter China's actions in the South China Sea.

The South China Sea remains one of Asia’s most volatile flashpoints.

Beijing claims almost the entire region, while ASEAN members the Philippines, Vietnam, Malaysia and Brunei also claim ownership of coastal areas and features. 

The Philippines, a key US ally, has had frequent clashes with China’s maritime fleet. 

Manila has repeatedly urged a stronger regional response, but ASEAN has traditionally sought to balance caution with economic ties to Beijing, the region’s largest trading partner.