China, which claims Taiwan as part of its territory even though the Chinese Communist Party has never ruled the island, last week responded to Lai’s inauguration with large-scale military drills, surrounding the island in a blockade-style exercise that involved more than 100 aircraft and dozens of warships.

“America is and always will be a reliable partner, and no amount of coercion or intimidation will slow down or stop the routine visits by the Congress to Taiwan,” Rep. Michael McCaul (R-Tex.), chairman of the House Foreign Affairs Committee and leader of the delegation, said Monday at a joint news conference with Lai.

McCaul, who traveled with Reps. Young Kim (R-Calif.), Joe Wilson (R-S.C.), Andy Barr (R-Ky.), Jimmy Panetta (D-Calif.) and Chrissy Houlahan (D-Pa.), said the delegation had come to demonstrate the U.S. commitment to Taiwan and understand the Lai administration’s priorities and objectives — a typically bipartisan approach for U.S. administrations and lawmakers, but also one that Republicans have increasingly scrutinized as China ramps up its military displays and other actions to isolate Taiwan.

China has criticized U.S. interactions with Taiwan, particularly by high-level officials, as a violation of the sovereignty it claims over the island. In 2022, in reaction to a visit to Taiwan by then-House Speaker Nancy Pelosi (D-Calif.), China launched a barrage of missiles into the sea near Taiwan in a retaliatory show of force.

“China urges relevant U.S. lawmakers to stop playing the ‘Taiwan card,’ stop meddling in China’s internal affairs, stop supporting and indulging ‘Taiwan independence’ secessionist forces, and stop damaging China-U.S. relations and the peace and stability in the Taiwan Strait,” Chinese Foreign Ministry spokeswoman Mao Ning said in a news briefing Monday, after Lai’s televised meeting with the lawmakers.

The United States has maintained formal relations with China since 1979, under a one-China policy that acknowledges Beijing’s claims over the island democracy without endorsing them. But it also has less-formal ties with Taiwan, operating the American Institute in Taiwan — an embassy in all but name — and selling arms to Taiwan to help it defend itself.

The island has seen a dramatic increase in congressional visits over the past three years, as lawmakers have expressed growing concerns about the potential for a Chinese invasion of the island. Last year, then-House Speaker Kevin McCarthy (R-Calif.) hosted Lai’s predecessor at a gathering of members of Congress in California, marking the highest-level meeting to date on U.S. soil. The rise in such exchanges has infuriated Beijing.

Last week, the Chinese government took the rare step of calling for an end to congressional delegations to Taiwan, going beyond its more general opposition to interactions between Taiwanese and U.S. officials.

“They sent me a warning: ‘Do not visit Taiwan because you’re in violation of the one-China policy,’” McCaul told reporters Monday at a joint news conference with Taiwanese Foreign Minister Lin Chia-lung. “I say to them: They’re in violation.”

In a largely symbolic move, China also has issued sanctions against U.S. lawmakers. Most recently, Beijing sanctioned former representative Mike Gallagher (R-Wis.), who served until recently as chairman of the House Select Committee on the Chinese Communist Party and has called for a more confrontational U.S. policy toward China. In May, months after Gallagher led a congressional delegation to Taiwan, Beijing said it would freeze the congressman’s current and future assets in China and deny him entry to the country. The Hudson Institute, a think tank where Gallagher serves as a fellow, said he had no assets there.

Beijing also distrusts Lai, who advocated earlier in his career for Taiwan’s formal independence and whom Beijing has branded a “worker for Taiwan independence.” Lai has since tempered his views and is now a key proponent of his party’s efforts to maintain peace with Beijing while repelling its aggression.

Lai pledged in his inaugural speech to continue his predecessor’s approach to maintaining the cross-strait status quo. But he and the visiting American lawmakers on Monday also spoke of their determination to increase the island’s cooperation with Washington and the need to bolster Taiwan’s defenses.

“I deeply admire former president Ronald Reagan’s approach of ‘peace through strength,’” Lai said Monday in his first remarks as president to international media outlets. “Therefore, moving forward, I will enhance reform of and bolster national defense, demonstrating to the world the Taiwanese people’s determination to defend our homeland.”

He thanked Congress for its recent approval of supplemental security assistance for Taiwan. “We will continue to deepen cooperation with the U.S. and other like-minded countries to jointly maintain regional peace, stability and prosperous development,” Lai said.

The United States cut its formal ties with Taiwan as part of its official recognition of China. But it has continued under multiple administrations to have an informal relationship with Taiwan, under the terms of the Taiwan Relations Act. The 1979 act authorizes U.S. funding for Taiwan’s defenses and lays out U.S. opposition to any moves by China to seize or harass the island.

Chinese President Xi Jinping has repeatedly indicated in recent years that China is willing to take Taiwan by force, if necessary, and has said that China’s “reunification” with Taiwan, now a self-governing island of 23 million people, is “inevitable.”

The Biden administration and Congress have gradually expanded U.S. support for Taiwan in response, including $4 billion in recently approved security assistance for the region. McCaul reiterated that support but added, “We do have to be careful with certain red lines we know the PRC has — not to cross those lines, because that would end up in a catastrophic war,” referring to China by its official name, the People’s Republic of China. McCaul did not say how lawmakers define those red lines.

But with a U.S. presidential election looming, Republicans have also been increasingly critical of President Biden’s foreign policy agenda, including what they characterize as an insufficiently bold response to Chinese aggression.

“We need to communicate strength and deterrence to communist China, which means that we follow through with these defense articles,” Rep. Andy Barr, a co-chair of the Congressional Taiwan Caucus and a delegation member, said in an interview Monday. Barr added that the United States needed to become “more integrated” with Taiwan “militarily, economically and diplomatically.”