The United States military is preparing for a possible increase of the number of troops in Taiwan amid worries that China is preparing to invade the territory they have long claimed as theirs.

While Russia continues its invasion of Ukraine and is working on a possible arms deal with China, the Chinese are looking at upping their timetable for a Taiwan invasion, according to reports. As a result, the U.S. is getting ready to drastically increase its presence. Via the Wall Street Journal:

The U.S. plans to deploy between 100 and 200 troops to the island in the coming months, up from roughly 30 there a year ago, according to U.S. officials. The larger force will expand a training program the Pentagon has taken pains not to publicize as the U.S. works to provide Taipei with the capabilities it needs to defend itself without provoking Beijing.

The number of American troops, which has included special-operations forces and U.S. Marines, has fluctuated by a handful during the past few years, according to Defense Department data. The planned increase would be the largest deployment of forces in decades by the U.S. on Taiwan, as the two draw closer to counter China’s growing military power.

Beyond training on Taiwan, the Michigan National Guard is also training a contingent of the Taiwanese military, including during annual exercises with multiple countries at Camp Grayling in northern Michigan, according to people familiar with the training.

According to U.S. officials, the force increase has been planned for months, well before the sudden tensions between the U.S. and China over a suspected spy balloon flew over the U.S. mainland.

The new troops will be tasked with training Taiwan’s military on U.S. weapons systems and tactical maneuvers, possibly indicating that U.S. intelligence feels an invasion is more likely than ever before. This level of coordination has made Chinese officials nervous, according to some reports, with China accusing the U.S. of violating previous promises to remain neutral.