China's military appears to be preparing for widely anticipated drills in response to a recent visit by Taiwan's president to Hawaii and Guam.

Taiwan's defense ministry said Monday that it detected Chinese naval and coast guard ships entering the Taiwan Strait and the western Pacific and that China had restricted airspace along its southeast coast through Wednesday.

There was no immediate confirmation from the Chinese side.

A Taiwan defense ministry statement said it has set up an emergency response center and launched combat readiness exercises. It did not say what those exercises entailed.

The Chinese government says Taiwan is part of its territory and opposes American support and military sales to the self-governing island. Taiwanese President Lai Ching-te made stops in Hawaii and Guam during a weeklong tour of the Pacific that ended Friday.

China maintains Taiwan is a province that should not have its own president or foreign relations.

"It must be pointed out that there is no such thing as a defense ministry in Taiwan," Chinese Foreign Ministry spokesperson Mao Ning said when asked about the Taiwanese statement. "Taiwan is part of China, and the Taiwan issue is China's internal affairs. China will firmly safeguard national sovereignty and territorial integrity."

China, which views Lai as a separatist, held major military exercises around Taiwan following his inauguration in May and his national day speech in October. It also held a major drill after Nancy Pelosi, then the speaker of the House of Representatives, visited Taiwan in 2022.

The Taiwan defense ministry statement said China had restricted air space in seven zones off Fujian province, which faces Taiwan, and off Zhejiang province, which stretches north from Fujian to Shanghai.