BEIJING/TAIPEI (Reuters) – Taiwan President Lai Ching-te is escalating tensions with “sinister intentions”, China’s government said, ahead of a keynote speech Lai will give in Taipei that could set off a Chinese military response.

Lai, who took office in May after winning election in January, is detested by China which calls him a “separatist”. Beijing claims democratically governed Taiwan as its own territory, a view Lai and his government reject.

Responding late on Tuesday to comments Lai gave at the weekend on how it is “impossible” for the People’s Republic of China to become Taiwan’s motherland because Taiwan has older political roots, China’s Taiwan Affairs Office said he was confusing right from wrong.

Lai continues to peddle a theory that the two sides of the Taiwan Strait are two separate countries, it said in a statement.

“Lai Ching-te’s Taiwan independence fallacy is just old wine in a new bottle, and again exposes his obstinate stance on Taiwan independence and his sinister intentions of escalating hostility and confrontation,” it added.

Lai will give his main national day speech on Thursday, which marks the overthrow of the last Chinese dynasty in 1911 and the ushering in of the Republic of China.

The defeated republican government fled to Taiwan in 1949 after losing a civil war with Mao Zedong’s communists. The Republic of China remains Taiwan’s formal name.

China is likely to launch military drills near Taiwan in response to Lai’s speech as a pretext to pressure the island to accept its sovereignty claims, Taiwanese officials say.

A U.S. State Department spokesperson said they could not speculate on what China would or would not do.

“However, it is worth emphasising that using routine annual celebrations or public remarks as a pretext or excuse for provocative or coercive measures undermines peace and stability,” the spokesperson said.

Lai says only Taiwan’s people can decide their future, and has repeatedly offered talks with Beijing but been rebuffed.

China staged “punishment” war games around Taiwan shortly after Lai’s May inauguration.

(Reporting by Beijing newsroom and Ben Blanchard; Additional reporting by Michael Martina in Washington; Editing by Michael Perry)