President Xi thundered against past efforts in Taiwan to become legally independent of China and said the two sides should pursue a "one country-two systems" model of unification that his government applied to Hong Kong in 1997.
The primary goal of Xi's speech, said a Taiwanese analyst, is to send a message to the United States that China would not tolerate any interference from Washington in the Taiwan issue.
The implementation of the "one country, two systems" policy in Hong Kong has deprived its people of freedom and the rule of law - something the people of Taiwan will never accept, the MAC said.
"We have never accepted the "1992 consensus.' The fundamental reason is because the "1992 consensus" as defined by Beijing is in fact the 'one China principle" and 'one China, two systems" formula", Tsai said.
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".
No one or no party can stop the trend toward unification, the Chinese leader said in a speech devoted to Taiwan, calling independence for the self-governing island against history and a dead-end.
The Chinese president spoke on the 40th anniversary of a 1979 New Year's pledge by China to halt bombardment of Taiwanese islands in hopes of attaining the "sacred mission" of bringing the two sides together.
All told, the speech amounted to a more balanced tack at a juncture when Taiwan is gearing up for presidential elections, and mainland officials - and Taiwanese politicians - see an opportunity to press their case.
On New Year's Day, Tsai said in a national speech that her loss at the November polls had nothing to do with Taiwanese voters' willingness "to abandon our sovereignty" and accused China of interfering in Taiwanese politics.
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Beijing "reserves the option of taking all necessary measures" against outside forces that interfere with peaceful reunification and Taiwanese separatist activities.
Xi also stressed that "foreign interference is intolerable", and that his government "will not promise to renounce the use of force".
"I don't think the speech was negative", said David Lu, vice president of the equity department at Taishin International Bank in Taipei.
She added that Beijing "must respect the insistence of 23 million people for freedom and democracy" and "must use peaceful and equal terms to handle our differences".
Beijing has regularly sent military aircraft and ships to circle the island on drills in the past few years and has heaped pressure on the island internationally, including whittling down its few remaining diplomatic allies.
Xi described unification under a "one country, two systems" approach that would "safeguard the interests and well-being of Taiwanese compatriots".
In mid-term elections a year ago, the DPP suffered losses causing Tsai to resign as party leader, while the pro-China opposition rival Kuomintang made gains.
Decades later, China has again been rebuffed. Nationalist forces under Chiang Kai-shek fled to Taiwan in December 1949 after losing a civil war to the Communists.