"We are collaborating, working very diligently with the Vietnamese. The Vietnamese filled out their Coast Guard multi-fold," Admiral Karl L. Schultz of the U.S. Coast Guard (USCG) told a press conference via phone on Tuesday.

He was answering a question about what the USCG has planned on doing to help countries in the region ensure their navigation and aviation freedom, given China increasing its military presence.

Schultz recalled his recent meetings with leaders of the Vietnam Coast Guard, saying Vietnam was one of the first nations in the region to receive the Hamilton-class patrol boat, a high endurance cutter.

In 2017, the U.S. sent Vietnam a Hamilton-class patrol boat, a high endurance cutter named USCGC Morgenthau, via the Excess Defense Articles (EDA) program in 2017.

Before handing over the USCGC Morgenthau, which has been renamed CSB 8020 by the Vietnam Coast Guard, the U.S. had trained Vietnamese coast guards in Hawaii.

Regional countries can use such resources and take initiatives to guarantee their sovereignty benefits in the region, the admiral said.

He said the USCG has a long-term commitment to supporting countries in the Indo-Pacific region, including activities like transferring patrol vessels, organizing multi-nation joint drills, signing agreements on rescue missions, and sharing technical expertise.

The USCG National Security Cutter Bertholf (WMSL-750) patroled the Western Pacific as part of the Indo-Pacific Command's operations from January to mid-June while another cutter, Stratton, is in the region now.

Schultz said the U.S. Coast Guard presence in the area will hopefully reinforce the practice of international protocol and a free and open rule-based mindset, calling that "an important, national U.S. interest."

It can also serve as a reminder of how the international norms should be established and reinforced, he said.

The U.S. and China are at odds over increasing military presence in the Indo-Pacific region. China has repeatedly opposed U.S.’s patrols to maintain navigation freedom in the South China Sea, which Vietnam calls the East Sea, while Washington and Southeast Asian countries have expressed concerns about China’s militarization of artificial islands in the sea.

The U.S. State Department said last Saturday it was concerned by reports of China’s interference with Vietnam and other countries' oil and gas exploration and exploitation activities. The statement came after Vietnam denounced the presence of Chinese survey ship, Haiyang Dizhi 8, and its escorts in the southern area of the East Sea which Vietnam, calling it a violation of the country's exclusive economic zone (EEZ) and continental shelf.

"China’s repeated provocative actions aimed at the offshore oil and gas development of other claimant states threatens regional energy security and undermines the free and open Indo-Pacific energy market," the U.S. department said.