Lawmakers from both the House and Senate landed in the country Wednesday morning to a warm welcome from Taiwan President Tsai Ing-wen. The Chinese government soon released a statement condemning the visit.
The lawmakers visiting were Republican Sens. Lindsey Graham of South Carolina, Ben Sasse of Nebraska, Richard Burr of North Carolina, and Rob Portman of Ohio, Republican Texas Rep. Ronny Jackson, and Democratic New Jersey Sen. Bob Menendez.
The lawmakers are among the most high-level U.S. officials to visit Taiwan. Mainland China argues Taiwan is a rogue region of China and not an independent country.
The U.S. has tenuously respected that designation for decades, even while sending military aid and occasional visits from U.S. officials to support Taiwan.
"China firmly opposes any form of official interaction between the U.S. and China’s Taiwan region," the spokesperson for the Chinese government tweeted Thursday.
Fears that China may move to invade Taiwan have risen in recent years, thanks to China's increasing aggression in the region, including frequent air force flights near Taiwan's airspace.
The issue has also been highlighted thanks to Russia's invasion of Ukraine. Observers say Russia's invasion may embolden China to take action on its own.
The U.S. delegation in Taiwan will meet with President Tsai and is scheduled to depart Friday.