Marines disembark from an amphibious combat vehicle during a training exercise at Marine Corps Air Ground Combat Center Twentynine Palms, Calif. Photo courtesy Marine Corps.

While arguing for a new arms spending package this week, Taiwan’s defense minister, Chiu Kuo-cheng, warned that military tensions with China are the worst in 40 years and that Beijing could be able to launch a “full-scale” invasion by 2025, Military.com reported.

If recent media reports are true, the US appears to be taking that imminent threat very seriously.

In a move that might raise tensions even further between the US and China, press reports suggest that US special operations forces and Marines have been secretly training Taiwan’s ground and maritime forces “for at least a year.”

According to the Wall Street Journal and citing unnamed US officials, a couple of dozen special operators and support troops are training small units of Taiwan’s ground forces, while a contingent of Marines is working with local maritime forces on small-boat training.

The news came amid a record-setting number of Chinese military flights around the island.

The People’s Liberation Army (PLA) made a total of 149 military flights over four days, including 56 on Monday, The Associated Press reported.

US State Department Spokesman Ned Price called the Chinese activity “destabilizing” and “provocative.”

“We strongly urge Beijing to cease its military, diplomatic and economic pressure and coercion against Taiwan,” he said, calling US commitment to the island “rock-solid.”

And the flights are not likely to abate any time soon, says Dean Cheng, a top Chinese military expert at the Heritage Foundation.

“The Chinese are clearly going to keep doing this until the US backs off. That should worry us,” he said late last week. “They are exhausting the Taiwan air force; they are trying to intimidate them.”

Reuters news agency later reported two sources familiar with the issue saying the trainers had been rotating into Taiwan on a temporary basis.

The sources, who spoke on condition of anonymity, declined to say how long the training had been going on but suggested it started before Joe Biden took office as president in January.

Taiwan’s Defence Ministry declined to comment on the Journal report, but told Reuters “all military exchanges are carried out in accordance with annual plans.”

The Pentagon did not confirm or deny the report. Spokesman John Supple said US support for Taiwan’s military is gauged on its defence needs.

“Our support for and defence relationship with Taiwan remains aligned against the current threat posed by the People’s Republic of China,” Supple said in a statement.

“We urge Beijing to honour its commitment to the peaceful resolution of cross-Strait differences.”

The report appeared to confirm Taiwan media articles last November – which cited Taiwan’s Naval Command – that US troops had arrived there to train Taiwan marines and special forces in small-boat and amphibious operations, Al Jazeera reported.

Those reports were subsequently denied by US and Taiwanese officials, who emphasised the two sides were involved in bilateral military exchanges and cooperation.

The US maintains an ambiguous commitment to defend Taiwan and supplies it with military equipment and weapons, including missiles and fighter jets.

Beijing has not ruled out the use of force to take control of the island, which is separated from mainland China by a sea channel about 161km (100 miles) wide.

A video released last year and featured in Taiwan media showed US troops taking part in an exercise on the island dubbed “Balance Tamper.”

China’s foreign ministry issued a statement urging the US to stop military aid to Taiwan.

“China will take all necessary steps to protect its sovereignty and territorial integrity,” the statement said.

Hawkish state media outlet, the Global Times said on Friday that China’s state council “strongly opposed any form of military collusion” between Taiwan and the US.

“We urge the US to abide Three Communiqués on the Taiwan issue and stop any provocations. The DPP authorities work with external forces to seek ‘independence’ and reject reunification. This has led the people of Taiwan to disaster, and their attempts are bound to fail.”

As part of the “One China” policy, the US also does not formally have diplomatic relations with Taiwan.

But US ties with Taipei City, the capital of Taiwan, have deepened in recent years. In the defense sphere, that has included billions of dollars in arms sales.

The report came as President Tsai Ing-wen said on Friday that Taiwan will “do whatever it takes to defend its freedom and democratic way of life,” The Guardian reported.

“Taiwan does not seek military confrontation,” she told a security forum in Taipei.

“It hopes for a peaceful, stable, predictable and mutually beneficial coexistence with its neighbours. But Taiwan will also do whatever it takes to defend its freedom and democratic way of life.”

According to the Wall Street Journal report, the trainers in Taiwan rotate in and out, so it does not represent a permanent presence.

There have been reports of US military advisers there over the years but Julian Ku, a law professor at Hofstra University, said the significant factor in these reports is the apparent confirmation by US officials.

“It’s an open secret they’ve been doing training exercises here and there, but this is a big deal to publicly acknowledge them,” Ku said.

“I don’t know what the benefit of that is. The Chinese government knows what’s going on. We’re not telling them — we’re just telling the Chinese public, which will then create pressure on the government to do something.”

Sources: Wall Street Journal, Military.com, Al Jazeera, Reuters, The Guardian, Breaking Defense