Taiwan hit back by calling China a troublemaker after Chinese President Lai Ching-tei said on Monday that military drills near Taiwan were punishment for Taiwan’s continued promotion of “separatism,” in a strong statement from Beijing.

China, which has never ruled out using force to bring democratically-ruled Taiwan under its control, has stepped up military and political pressure on the island in recent years.

Taiwan’s Defense Ministry said China had sent 54 Chinese warplanes, including J-10 jets and drones, to conduct “joint combat readiness patrols” — one in the morning and one in the afternoon — near Taiwan.

It said the Chinese planes flew in airspace north, west, southwest and east of Taiwan, and sent Taiwanese air and naval forces to keep watch.

Of those, 42 planes crossed the center line of the Taiwan Strait, an unofficial buffer between the two sides, the ministry said.

If the Lai administration “dare to provoke and play with fire, it will only bring its own destruction,” a spokesman for China’s Taiwan Affairs Office said in a statement.

Taiwan regularly reports such military activities in China, but the Chinese government rarely comments on them.

Taiwan’s Mainland Affairs Council said Beijing is destabilizing regional peace and stability by militarily threatening the island and raising tensions in the Taiwan Strait.

The Chinese Communist Party is a “troublemaker” in every sense of the word, the council said, and urged allies to stop China’s military expansion.

Taiwan’s defense officials have said China is trying to normalize exercises near Taiwan, and usually conducts such patrols near the island every 7-10 days.

Lai said last week that China has deepened its influence campaigns and aggression against the island, and vowed to take action against Beijing’s attempts to “absorb” Taiwan.

China considers Taiwan its territory, a claim rejected by the Taipei government.

Lai has repeatedly offered talks with Beijing but has been rebuffed. He says only the people of Taiwan can decide their future.