China, which claims Taiwan as its own territory, opposes any foreign interactions or visits by the island's leaders, especially those involving the United States.
Lai's week-long trip begins on Saturday, making what is officially called a stopover first in Hawaii before going to Marshall Islands, Tuvalu and Palau, three of the 12 countries which have formal ties with Taiwan, Reuters reported.
He will also stop over in the US territory of Guam.
Mao Ning, a spokesperson for China's foreign ministry, reiterated comments made by President Xi Jinping to US President Joe Biden at an Asia Pacific summit in Peru this month, in which he said "separatist acts" were incompatible with peace and stability in the Taiwan Strait.
"If the United States wants to maintain peace in the Taiwan Straits, it is crucial for it to recognize the independence nature of Lai Ching-te and the Democratic Progressive Party authorities," she said, referring to the ruling party.
The United States must "handle the Taiwan issue with utmost caution, unequivocally oppose Taiwan independence of Taiwan, and support the peaceful reunification of China", Mao added at a daily news briefing in the Chinese capital.
China opposes any "scurrying to the United States" of Taiwan's leaders, in any form, or any US support for separatist activities, she said.