China has decided the status quo of Taiwan’s situation is no longer acceptable and has begun to ratchet up pressure on the self-governing island, including holding out the possibility of using force, U.S. Secretary of State Antony Blinken said on Wednesday.

Speaking at an event organized by Bloomberg, Blinken said China had altered a decades-old basic understanding between Washington and Beijing that its differences with Taiwan would be managed peacefully.

“What’s changed is this: the decision by the government in Beijing that that status quo was no longer acceptable, that they wanted to speed up the process by which they would pursue reunification,” Blinken said.

He added that China has also made decisions on exerting more pressure on Taiwan and holding out the possibility of “using force to achieve their goals” if pressure tactics do not work.

“That is what has fundamentally changed.”

Washington did not want a “Cold War” and was not trying to restrain China, he added, but was resolute and standing up for its interests.

Last week, the top U.S. diplomat said Beijing was determined to pursue reunification with Taiwan “on a much faster timeline,” though he did not specify a date.

President Joe Biden’s administration has repeatedly accused China of using a visit to Taiwan in August by U.S. House Speaker Nancy Pelosi as a pretext to ramp of military drills around the island, which Beijing claims as its own territory.

The top U.S. general said last year that China was unlikely to try to militarily seize Taiwan in the next couple of years and the commander of the U.S. Indo-Pacific Command at that time told Congress this threat could manifest itself within six years.

China’s leader Xi Jinping told the five-yearly congress of China’s ruling Communist Party this month that Beijing would never renounce the right to use force over Taiwan, but that it would strive for a peaceful resolution.