In a major address on Wednesday, Mr. Xi promised economic gifts to Taiwan if it places itself under Beijing's rule, saying "with the great motherland's support, Taiwan compatriots' welfare will be even better, their development space will be even greater."

What China calls "reunification" should happen peacefully and Beijing would protect Taiwan's freedoms, Mr. Xi said, specifically pointing to the Hong Kong model of "one country, two systems" as a Taiwanese solution.

It was a notion that Taiwan's President Tsai Ing-wen immediately rejected Wednesday amid concern that Mr. Xi is directing what Lai I-chung, who chairs the International Cooperation Council of Taiwan think tank, called a "major policy change."

"Xi Jinping is eager to take unification with Taiwan as a matter of higher urgency," Mr. Lai said.