China has pledged “resolute countermeasures” following the United States’ decision to approve more arms sales to Taiwan, just hours before the island’s President William Lai Ching-te made a transit through the state of Hawaii, which further angered Beijing.

In a statement on Sunday, the Ministry of Foreign Affairs said the US arms sale to Taiwan sends “a wrong signal” to the island’s  Taiwan independence forces and undermines US-China relations.

“China will closely follow the developments and take resolute and strong measures to defend our nation’s sovereignty and territorial integrity,” it added.

The US is bound by law to provide Taiwan with the means to defend itself despite the lack of formal diplomatic ties between Washington and Taipei, to the constant anger of Beijing.

Taiwan rejects China’s claims of sovereignty.

The US State Department had approved the potential sale, worth an estimated $385m, of spare parts and support for F-16 jets and radars to Taiwan, hours before Lai began his trip to three Pacific nations, with stops in Hawaii and the US territory of Guam.

In a separate statement issued by a Foreign Ministry spokesman on Sunday, China said it “strongly condemned” the US for “arranging” Lai’s stopover, during which he was welcomed by Hawaii Governor Josh Green.

The statement added that it has “lodged serious protests with the US”.

The ministry added it firmly opposes any official exchanges between the US and Taiwan.

China, which views democratically governed Taiwan as its own territory and the most important issue in its relations with Washington, strongly dislikes Lai, calling him a “separatist”.

During Lai’s transit in Hawaii, he visited the USS Arizona Memorial at Pearl Harbour, during which he said the US and Taiwan should “fight together to prevent war”.

“Peace is priceless, and war has no winners,” he said.

Looking relaxed in a Hawaiian shirt, Lai was given the “red carpet treatment” on the tarmac of Honolulu’s international airport, according to his office, which said it was the first time a Taiwanese president had been given such a welcome.

He was met by Governor Green as well as Ingrid Larson, managing director in Washington of the American Institute in Taiwan (AIT).

In his first public speech of the weeklong trip, Lai said he was “grateful” to the US for its assistance in helping to ensure the success of the tour.

After Hawaii, Lai will visit Taiwan’s allies, the Marshall Islands, Tuvalu and Palau – the only Pacific island nations among the 12 countries that recognise Taiwan’s claim to statehood.