Marshall Islands President Hilda Heine extended Lai a "very warm welcome" after his arrival in the capital Majuro.

"Taiwan and the Marshall Islands share a traditional Austronesian culture as well as the values of freedom and democracy," Lai said in his response, speaking through an interpreter.

Lai spent two days in the United States, where he discussed "China's military threats" towards Taiwan during a call with former US House speaker Nancy Pelosi, and met with US government officials and members of Congress.

China opposes any international recognition of Taiwan and its claim to be a sovereign state. It especially bristles at official contact between the island and Washington, Taiwan's most important security backer.

The Marshall Islands is one of three Pacific island allies that Lai will visit as part of his first overseas trip since taking office in May. The others are Tuvalu and Palau.

They are among the 12 remaining nations, including the Vatican, that recognise Taiwan's claim to statehood after others were poached by China with promises of aid and investment.

- 'Long-time friends' -

China, which insists Taiwan is part of its territory, has fumed over recent US arms sales to the island and Lai's stop in the US island state of Hawaii, where he was welcomed with red carpets and garlands of flowers.

Lai is scheduled to hold talks with Heine and her cabinet, address the Marshall Islands' parliament and attend an evening banquet.

Pelosi's long-standing support for Taiwan has infuriated China, which responded to her visit to Taipei in 2022 with massive military drills around the island.

Lai and Pelosi discussed "China's military threats toward Taiwan", presidential spokeswoman Karen Kuo told reporters in Hawaii, describing the 20-minute call between the "long-time friends" as "warm and amicable".

In response to Lai's conversation with Pelosi, China on Monday called on the United States to "stop meddling with Taiwan" and cease "supporting and indulging Taiwan independence separatist forces".

"The Taiwan issue is the core of China's core interests and the first red line that cannot be crossed in China-US relations," foreign ministry spokesman Lin Jian told reporters in Beijing.

In his first public speech of the trip, Lai said Saturday that we have to "fight together to prevent war," warning there were "no winners" from conflict.

On the eve of Lai's week-long Pacific tour, the United States approved a proposed sale to Taiwan of spare parts for F-16s and radar systems, as well as communications equipment, in deals valued at $385 million in total.