Yinan He, an associate professor at the Department of International Relations at Lehigh University, said that Lee had been the first Taiwan leader to float the idea of the island being a separate distinct entity from mainland China.

"That makes him No. 1 or No. 2 most-hated person on Beijing's list for Taiwan. So by paying tribute to this person the Trump administration is really poking Beijing in the eye," she said.

The US State Department announced Thursday that Krach was on his way to Taiwan for the memorial service, but didn't give any further information on his schedule or his plans while in Taipei. "As Taiwan's first democratically elected president, Lee ushered in a new era of democracy, economic prosperity, openness, and rule of law," State Department spokeswoman Morgan Ortagus said on her official Twitter account.

China's Ministry of Foreign Affairs spokesman Wang Wenbin said Thursday that the US and Taiwan must "immediately stop" official exchanges. "China firmly opposes any form of official exchanges between the United States and Taiwan. This position is consistent and clear," added Wang.

Military tensions rise

Krach's visit comes as Beijing has been ramping up military pressure on Taiwan, holding drills in waters close to the island and flying fighter jets into airspace claimed by Taipei.

On Friday, China's Ministry of Defense announced new military exercises in the Taiwan Strait, which spokesman Ren Guoqiang called "a legitimate and necessary action" in response to warming US-Taiwan relations.

"Whether [the purpose of the liaison] is to use Taiwan to control China, or for Taiwan to rise based on foreign power, it is doomed to be a dead end. Those who play with fire will burn themselves," Ren said at a press conference.

It is just the latest in a series of Chinese military exercises which have been held around Taiwan in the past few weeks. On Wednesday, less than 24 hours before Krach left for Taiwan, two Y-8 Anti-Submarine Aircraft flew two sorties into Taiwan's Southwest Air Defense Identification Zone (ADIZ), according to the island's Defense Ministry.

Taiwan's military ordered the two planes to leave the island's airspace before dispatching aircraft to monitor them.

"These military actions have seriously roiled Taiwan and threaten peace and stability in the region," Vice Defense Minister Chang Che-ping said at a news conference. Taiwan's news agency CNA said that about 30 planes had taken part in the drills, crossing into Taiwan's ADIZ at least 21 times.

Ma said that China was prepared to meet any interference in Taiwan's affairs or attempts at independence with "firm will, full confidence and sufficient capabilities."