STATE DEPARTMENT - The United States said it is deeply disappointed in Kiribati's decision to abandon its diplomatic ties with Taiwan, in favor of China.

Several Republican and Democratic lawmakers voiced grave concerns. A Senate panel plans to move forward with a congressional proposal that could "impose consequences on nations downgrading ties with Taiwan."

In a stern statement on Friday, a State Department spokesperson said "countries that establish closer ties to China primarily out of the hope or expectation that such a step will stimulate economic growth and infrastructure development often find themselves worse off in the long run."

The spokesperson said the U.S. supports the status quo in cross-Strait relations, which includes Taiwan's diplomatic ties and international space, as important to maintaining peace and stability in the region.

"China's active campaign to alter the cross-Strait status quo, including by enticing countries to discontinue diplomatic ties with Taiwan, are harmful and undermine regional stability. They undermine the framework that has enabled peace, stability, and development for decades," the spokesperson told VOA.

The Pacific island nation of Kiribati severed diplomatic ties with Taiwan on Friday, becoming the second country to do so this week and bolstering China's hand.

This comes as another blow to Taiwan, as its three decades' diplomatic relations with the Solomon Islands ended on Monday after the Pacific island state's cabinet voted in favor of switching ties to China.

"In the last couple weeks, the Solomon Islands and now Kiribati have cut formal ties with Taiwan under pressure from Beijing. Unless this behavior is confronted, Beijing will stop at nothing to isolate Taiwan internationally," Republican Senator Marco Rubio said.

The U.S. sees Taiwan as part of a network of Asian democracies, calling Taiwan "a democratic success story and a force for good in the world." Informal Taiwan-U.S. ties have improved under U.S. President Donald Trump.

Democratic Senator Bob Menendez, who is also ranking member of Senate Committee on Foreign Relations, also weighed in on Twitter.

Next week, the Senate Committee on Foreign Relations will consider the so-called TAIPEI Act, the Taiwan Allies International Protection and Enhancement Initiative Act, said Colorado Republican Senator Cory Gardner in a tweet.

"Kiribati ending diplomatic ties with Taiwan demonstrates a need for urgent action," said Gardner, who is the chairman of Senate Foreign Relations subcommittee on East Asia, the Pacific, and international cybersecurity policy.

The proposed bill will allow the secretary of state to consider "the expansion, termination, or reduction" of U.S. foreign assistance to countries that downgrade ties with Taiwan.

China's 'problematic behavior'

As China's influence in the region has grown, American officials frequently point out what they see as "a range of increasingly problematic behavior" that includes China's ongoing militarization of disputed features in the South China Sea, and "predatory" economic activities and investments seen to undermine good governance and promote corruption and human rights abuses.

"This should concern all countries," a State Department official told VOA.

Funds were promised by China in return for Kiribati's recognition, Taiwan Foreign Minister Joseph Wu said.

"According to information obtained by Taiwan, the Chinese government has already promised to provide full funds for the procurement of several airplanes and commercial ferries, thus luring Kiribati into switching diplomatic relations," Wu said.

One China principle

Chinese Foreign Ministry spokesman Geng Shuang said Kiribati's decision "fully testifies to the fact that the One China principle meets the shared aspiration of the people."

Geng added, "There is but one China in the world and the government of the People's Republic of China is the sole legitimate government representing the whole of China."

The two sides split after the 1949 civil war when Chiang Kai-shek's Nationalist forces were driven off the mainland by Mao Zedong's Communists and sought refuge on Taiwan. But Beijing considers the self-ruled island part of its territory and has vowed to take control of it, by force if necessary.

The U.S. switched diplomatic recognition from Taiwan to China in 1979, but U.S. presidents are bound by law to supply it with arms and come to its defense.

The nuance between Washington's "One China policy" and China's "One China principle" is that the U.S. stance leaves open the possibility that a future resolution could be determined peacefully by both China and Taiwan.