The U.S. Coast Guard has rejected comments by a Chinese diplomat that its recent boardings of Chinese fishing boats in the Pacific Islands alongside local police are illegal, saying the joint patrols are at the behest of Pacific nations to protect coastal fisheries.

U.S. Coast Guard Cutter Hamilton offloads approximately $457 million in cocaine, marijuana at Port Everglades.

Reuters reported last month that six Chinese fishing boats were found to be violating Vanuatu's fisheries law after being inspected by local police who were on board the first U.S. Coast Guard boat to patrol the waters of the Pacific Islands nation.

China's Ambassador to New Zealand Wang Xiaolong, in a letter circulated by the Chinese embassy on Friday, said the use of shiprider agreements between the U.S. and Vanuatu, Kiribati and Papua New Guinea to "carry out law enforcement activities against China's fishing vessels" was a violation of international law.

In the letter, Wang claimed the agreements are not binding on China's fishing fleet.

"China is not obliged to accept the law enforcement of countries other than coastal states for fishing activities in their exclusive economic zones," the letter said.

U.S. Coast Guard Rear Admiral Michael Day on Wednesday said the Chinese ambassador's statement was inaccurate and the bilateral shiprider agreements complied with international law.

"We do these boardings at the behest of those host nations who invite us to board, to work with them collaboratively in protecting their Exclusive Economic Zones," he said at a press conference in Honolulu to mark the return of the U.S. Coast Guard cutter Harriet Lane after its Pacific Islands patrol.

"A free and open Indo-Pacific is predicated upon the following of international rules and norms and laws, and I am happy to say the coast guard is complying with all international law and these are legal boardings."

Commander Nicole Tesoniero said shiprider agreements with Samoa, Fiji, Vanuatu and Papua New Guinea had resulted in 23 boardings of fishing boats operating in the "far reaches of the respective countries' exclusive economic zones", with 12 violations found by local police.

"The targeting of vessels within the exclusive economic zones as well as the enforcement actions were all dictated by our partners," she said.

In an interview in Sydney, Admiral John Aquilino, Commander of the U.S. Indo-Pacific Command, said China's fishing fleet in the South Pacific should be viewed as a "maritime militia", based on its activities in the South China Sea and East China Sea.

"Those fishing vessels are the maritime militia," Aquilino said.

"If it were to get to a time or place where we have a crisis, and you look at Scarborough Shoal or the Senkakus, those fishing vessels are fishing and then they will take on a mission of pressurizing the host nation or the nation whose exclusive economic zone they are operating in," he said.

In the letter, Ambassador Wang said China exercised strict supervision over its distant water fishing fleets, had "a zero tolerance attitude towards illegal fishing", and respected the sovereign rights of coastal states.

The U.S. Coast Guard patrols come after Vanuatu and Solomon Islands, Pacific Island nations with close ties to China, blocked a U.S. Coast Guard vessel from coming to port to refuel in 2022 and 2023 as it undertook a patrol for illegal fishing on behalf of the Pacific Islands Forum regional block.

Australia, New Zealand and Britain have also stepped up navy patrols for illegal fishing in partnership with Pacific Islands nations, many of whom do not have militaries or boats to monitor coastal waters and exclusive economic zones spanning millions of kilometres.

US Pacific boss ‘very concerned’ about Chinese aggression in region

The head of U.S. Indo-Pacific Command said on Tuesday that he was “very, very concerned” about China’s aggression toward Philippine forces near disputed islands in the South China Sea.

The Chinese coast guard has repeatedly clashed with Philippine patrol vessels near the Philippines-occupied Second Thomas Shoal. Last month, several Filipino seamen were injured when a Chinese vessel sideswiped a smaller Philippine vessel and another two Chinese coast guard ships used high-pressure water spray to shatter the Philippine vessel’s windscreen.

Asked if the submerged reef in the Spratly Islands was the most dangerous flash point in his area of command, U.S. Adm. John Aquilino told a forum at the Lowy Institute, a Sydney-based international policy think tank: “I’m very concerned about what’s happening at the Second Thomas Shoal.”

“I’m very, very concerned about the direction it’s going,” Aquilino said. “These actions are dangerous, illegal and they are destabilizing the region.”

“What’s next and how far are they willing to go in that area?” Aquilino asked.

The United States, Japan, the Philippines and Australia held their first four-way joint exercises in Philippine waters in the South China Sea on Sunday, which they said were intended to uphold freedom of navigation and overflight in a region contested by China.

Aquilino said the joint exercise demonstrated the nations’ ability to operate safely, effectively and lawfully in the region.

“Those types of events and things are exactly what we need to do to demonstrate that strength amongst the like-minded allies and partners and that we will continue to operate anywhere that international law allows,” Aquilino said.

China’s military said Sunday that it had conducted air and sea patrols and that all activities that “disrupt the South China Sea” are under control, an apparent response to naval exercises by the U.S. and its allies.