A group of U.S. lawmakers arrived in Taiwan on Tuesday night by military aircraft, prompting a rebuke from China, with its military conducting a "combat readiness patrol" near the Taiwan Strait.

According to the South China Morning Post, a Hong Kong newspaper, the lawmakers group consists of four senators, including John Cornyn and Tommy Tuberville, and two members of the House of Representatives, all Republicans.

Combined photo shows Taiwan flag and U.S. flag. (Kyodo)

The military plane carrying the lawmakers flew into Taipei on the self-ruled island from Manila, according to Taiwanese media. They are reportedly scheduled to hold talks with Taiwan President Tsai Ing-wen.

Meanwhile, Taiwan's Defense Ministry said six Chinese warplanes entered a Taiwan-designated air defense identification zone on Tuesday.

U.S. Defense Department press secretary John Kirby told reporters that congressional delegation visits to Taiwan are "not unusual" and the latest one is in "keeping with our obligations under the Taiwan Relations Act," which governs Washington's unofficial ties with Taipei.

China regards Taiwan as a renegade province and has vowed to reclaim it, by force if necessary.

"The U.S. act has wantonly interfered in China's internal affairs, seriously undermined China's territorial sovereignty and posed a severe threat to peace and stability in the Taiwan region," a Chinese Defense Ministry spokesperson said Tuesday, according to state-run Xinhua News Agency.

The Eastern Theater Command of the People's Liberation Army, China's military, said Tuesday it had conducted a joint combat readiness patrol near the Taiwan Strait to improve the joint combat capability of multiple military services and branches, according to the Global Times, a tabloid of the Communist Party.

U.S. officials have visited Taiwan more frequently since last year. In August 2020, then Health and Human Services Secretary Alex Azar visited Taiwan. The following month, Keith Krach, undersecretary of state for economic growth, energy and the environment, also traveled to the island.

This year, an unofficial delegation including a former senator visited Taiwan in April, followed by a visit by several senators in June.

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