War has no winners and peace is priceless, Taiwan President Lai Ching-te said on Saturday in Hawaii after visiting a memorial to the attack on Pearl Harbor on a trip to the United States that has angered Beijing.

Lai is making a sensitive two-day trip to Hawaii that is officially only a stopover on the way to three Pacific island nations that maintain formal ties with Taiwan, which China claims as its territory.

Speaking to members of the overseas Taiwan community and Hawaii politicians, including members of Congress Ed Case and Jill Tokuda, Lai referred to his visit to the USS Arizona Memorial earlier in the day and laid a wreath in memory of those who died in the 1941 Japanese attack.

“Our visit to the memorial today in particular reminds us of the importance of ensuring peace. Peace is priceless and war has no winner. We have to fight —fight together — to prevent war,” Lai said in English, in a speech carried live on television in Taiwan.

As Lai was attending the event, China said it had complained to Washington for arranging for his transit through US territory, while vowing “resolute countermeasures” against a potential arms sale to Taiwan that the US announced hours before Lai started his trip.

China’s foreign ministry lodged “stern representations” over the transit, China’s Taiwan Affairs Office said in a statement.

“We are firmly opposed to official exchanges between the United States and Taiwan, and we are firmly opposed to the ‘transit’ of leaders of the Taiwan region to the United States under any name and for any reason,” it said.

Security sources have told Reuters that China could launch a new round of war games around Taiwan in response to his visit, his first overseas trip since assuming office in May, having won the election in January.

China has staged two rounds of major war games around Taiwan so far this year.

In his speech, Lai switched to Taiwanese, also known as Hokkien, and said that by uniting together, all difficulties could be overcome. “Taiwan’s democracy can become a model for the international community,” he said.

Lai and his government reject Beijing’s sovereignty claims and say they have a right to visit other countries.

After Hawaii, Lai will go to the Marshall Islands, Tuvalu and Palau, with another stopover in the US territory of Guam. Hawaii and Guam are home to large US military bases.