China claims Taiwan as part of its territory and has said it will never renounce the use of force to bring it under Beijing's control.

In recent years, Beijing has upped military and political pressure on the Taipei government, with the latest show of force coming three days after Lai's inauguration, when China conducted war games around the island.

Speaking at a press conference Wednesday marking his first month in office, Lai said: "The annexation of Taiwan is a national policy of the People's Republic of China".

"In addition to military force, they have increasingly employed non-traditional methods of coercion to try to force Taiwan into submission," he said.

"However, Taiwan will not bow to the pressure. The people of Taiwan will resolutely defend national sovereignty and uphold the democratic and free constitutional way of life."

He also reiterated that Taiwan would seek "to avoid conflict".

"The people of Taiwan love peace and are kind to others, but peace must be backed by strength... True peace is not just empty words, peace guaranteed by strength is real peace," he said.

China had said the war games -- launched days after Lai's May 20 inauguration -- were "punishment" for his inaugural speech, which Beijing dubbed a "confession of Taiwan independence".

Encircling Taiwan with warships, fighter jets and coastguard vessels, China said the three-day drills -- dubbed Joint Sword-2024A -- were a test of its ability to seize control of the island.

After the exercises, Beijing vowed military pressure would continue "as long as 'Taiwan independence' provocations continue".

Taiwan -- separated from China by a narrow strait -- has its own government, military and currency.

Lai is regarded as a "dangerous separatist" by China and has hewed closely to the rhetoric of his predecessor Tsai Ing-wen, saying that there is no need for Taiwan to formally declare independence as it is "already independent".

But Lai and Tsai's Democratic Progressive Party has long stood on a platform of Taiwanese sovereignty, and China has not conducted top-level communications with Taipei since 2016.

Since his election in January, Lai has signalled an openness to resuming dialogue with China, including calling for both sides to develop exchanges in his May inaugural speech.

However, China has appeared to rebuff those overtures.

It continues to maintain a near-daily presence of naval vessels and warplanes around the island, so-called grey zone tactics that fall short of an outright act of war but serve to exhaust Taiwan's military.

In recent months, Chinese coast guard ships have also been spotted around Taiwan's outlying islands, at times briefly entering its restricted waters.