Nuku'alofa, TONGA — An initially positive response to news the United States plans to build an embassy in Tonga has turned sceptical.

US vice president Kamala Harris made the announcement among other 're-engagement' promises for the Pacific region, in an address via video link with leaders of the Pacific Islands Forum, yesterday, during the forum's annual leaders meeting.

RNZ Pacific correspondent in Tonga Kalafi Moala said people there now want to know if there will be consular services provided, so they don't have to travel to Suva to get visas.

China recently completed building a large embassy in Nuku'alofa, and Moala said people were asking - via social media and talkback radio - if that was why Washington had chosen Tonga for the new mission.

"One man in a talk back radio show this morning - raised [the question]: 'Do the superpowers have to come and carry out their political tug of war and their political battles in our own backyard? Why don't they go somewhere else and do it there.'

"So that's a lot of questions that are beginning to be raised here in Tonga."

The US also announced it would build an embassy in Kiribati.

Earlier this week Kiribati opposition leader Tessie Lambourne said Kiribati's decision to withdraw from the Pacific Islands Forum on the eve of its annual summit was driven by pressure from China.

Former Kiribati president Anote Tong said he suspected Kiribati had an agreement in the works with China, which could include exclusive access for Chinese vessels to the Phoenix Islands Protected Area - the largest designated marine protected area in the world.

But this week Chinese foreign ministry denied Beijing had any part in Kiribati's withdrawal from the forum.

"For years, China and the PIF have sound cooperative relations. I would like to stress that China does not interfere in the internal affairs of Pacific Islands countries (PICs) and hopes to see greater solidarity and closer cooperation among PICs for common development," spokesman Wang Wenbin said.