The American Institute in Taiwan, Washington’s de-facto embassy on the island, confirmed on Wednesday plans for the US Marines to be posted at its brand-new compound in Taipei’s Neihu district.

Hundreds of diplomats are set to move into the spacious complex, which is larger than the offices of many US embassies and consulates worldwide.

AIT spokeswoman Amanda Mansour also revealed that elite US troopers have already been guarding the institute’s existing offices since as early as in 2005, an arrangement in line with the US State Department’s practice to ensure the safety of its staff.

There have been active members of the four branches of the US military stationed at the AIT since 2005, the spokeswoman said.

It is the first time the AIT has publicly spoken about military officers stationed at the institute, but it is believed that these officers, including Marines, are all mandated to stay low-key and told not to wear uniforms when on duty to avoid causing sensitivity with Beijing.

The new compound of the American Institute in Taiwan, in Taipei’s Neihu district. Photo: Handout

Taiwan’s President Tsai Ing-wen, center, tours the new AIT compound. Photo: Handout

Taiwanese papers reported last year that US Marines would be posted at the new compound, as Washington’s gesture of closer ties with the self-ruled island, drawing anger from Beijing, which insists it has sovereignty over the breakaway province. Beijing’s bellicose mouthpiece, the Global Times, even claimed that such a move would constitute a “US invasion of China”.

The new AIT complex would be staffed by a small number of US citizens and a large number of Taiwanese, and US Marines would be posted to protect everyone inside the new facility, according to Taiwan’s Central News Agency.

Under a longstanding arrangement, the Pentagon provides Marine Corps for foreign service guard-duties at American embassies, legations and consulates at more than 140 overseas locations, under supervision of the Marine Embassy Security Command.

Meanwhile, AIT director Brent Christensen and Taiwan’s Foreign Minister Joseph Wu said on Wednesday that personnel would move into the building on May 6, and that the AIT would throw a large housewarming party at its Neihu office.

The AIT’s confirmation of US military personnel in Taiwan came as Washington warned Beijing against any use of force in regard to Taiwan, after the latter flew two People’s Liberation Army J-11 fighter jets to cross the median line of the Taiwan Strait on Sunday, Beijing’s first breach of the tacit border since 1999.

In response, Taiwan scrambled as many as five jets including an F-16 to expel the two Chinese warplanes, in a show of determination to fend off the PLA’s circumnavigations. Taiwan’s President Tsai Ing-wen, who reportedly ordered the interception, also convened an emergency meeting to formulate countermeasures.

US Department of State spokesman Robert Palladino said the US opposed unilateral action by any party aimed at altering the status quo, including anything related to force, and he called on Beijing to stop saber-rattling and resume dialogue with the democratically elected administration of Taiwan.