Analysts say China is widely regarded as if it had tried to influence local elections through economic pressure on the self-governing island, even discouraging tourism.
King said he expects China to reach KMT politicians before the next presidential vote in Taiwan at the start of 2020.
The election results left Tsai to falter, prompting her to resign from the DPP to take responsibility, even though she remains as president of Taiwan. Analysts, however, were divided on his political future.
"I still think that you will be the candidate (for the DPP in power), but there will be a challenge from within," King said. "It's an uphill battle."
The Kuomintang is now hoping that local polls will pave the way for the presidential election in 2020.
"The results were a great comeback for the KMT party, which initiated an intra-party reform process after losing presidential elections in 2016," the Eurasia Group's risk advice service said in an analysis carried out on Sunday. . "Beijing will see the results of these elections as a solid support for its campaign of pressure against the DPP."
The Eurasia group added that it sees Tsai – who is technically not in the runoff – as the biggest political loser of the weekend elections, with the DPP who will hardly support her for a second term in the hope that voters will accept someone else.