A member of the second U.S. congressional delegation to visit Taiwan this month said Friday that the self-ruled island is “on the rise,” as Beijing demanded the group “call off” their trip.

“I’m midway through my visit to Taiwan & this much is clear: this place is on the rise,” Rep. Elissa Slotkin, a Democrat from Michigan and a former U.S. intelligence official said on Twitter.

“The fortitude & determination of the people, led by their dynamic (frankly, kick-ass) President, is downright inspiring — and I don’t inspire easily. Democratic values still & always matter,” she added.

Slotkin and four other members of the U.S. House of Representatives arrived in Taiwan for a brief visit on Thursday at a time when Beijing has ramped up political and military pressure on the democratically governed island, including through a show of force over Taiwan’s air defense zone.

The Chinese Communist Party (CCP) claims the self-ruled island of Taiwan as a province of China. Taiwan has its own ruling party, constitution, and military. In a speech in October, Chinese leader Xi Jinping said he would achieve “reunification of the nation,” and called Taiwan’s independence a “serious hidden danger to national rejuvenation.”

Other members of the delegation are Democrats Mark Takano, chairman of the House Committee on Veterans’ Affairs, Colin Allred, Sara Jacobs, and Republican Nancy Mace, the de facto U.S. embassy in Taiwan said, noting that the lawmakers are due to leave the island on Friday.

“The congressional delegation will meet with senior Taiwan leaders to discuss U.S.-Taiwan relations, regional security, and other significant issues of mutual interest,” the Taipei branch of the American Institute in Taiwan said in a statement.

Shortly after arriving in Taiwan on Thursday, Slotkin said that her office received a message from the Chinese Embassy telling her to abandon the trip.

“When news of our trip broke yesterday, my office received a blunt message from the Chinese Embassy, telling me to call off the trip,” Slotkin wrote on Twitter.

“But just as with other stops, we’re here to learn about the region and reaffirm the U.S. commitment to our hosts, the Taiwanese,” she added. “I’m looking forward to an informative trip.”

It marks the second trip by U.S. lawmakers to the island this month. On November 9, members of the Senate and House of Representatives traveled to Taiwan for a low-profile diplomatic visit, meeting Taiwanese President Tsai Ing-wen on November 10.

During a press briefing on Friday, Chinese Foreign Ministry spokesman Zhao Lijian said Beijing was “strongly dissatisfied” with the lawmakers’ visit.

“They are sending a seriously wrong signal of supporting the Taiwan independent separatist forces,” he said.

During a meeting with Tsai on Friday morning, Takano said Washington’s commitment to Taiwan is “rock solid.”

U.S. commitment to the island “has remained steadfast as the ties between us have deepened,” he said.

“Taiwan is a democratic success story, a reliable partner, and a force for good in the world,” Takano added.

Earlier this month, Republican Sen. Josh Hawley of Missouri unveiled a bill that aims to bolster Taiwan’s ability to defend itself against a potential attack by China, citing warnings from Taiwanese and U.S. officials that “China may try to invade Taiwan over the next few years.”

“We must do everything in our power to help Taiwan urgently strengthen its defenses,” Hawley said in a statement. “If China’s recent actions have shown anything to the world, it’s that Beijing will stop at nothing in its quest to dominate the Indo–Pacific and then the world. We must not let them succeed.”

Although Washington maintains a decades-long foreign policy known as “strategic ambiguity,” it is required to provide Taiwan with military equipment for its self-defense under the Taiwan Relations Act (TRA).

This article was written by Isabel Van Brugen and originally published on Newsweek.