The number of people prosecuted for spying for Beijing has soared, with retired and serving members of Taiwan's military the main targets of Chinese infiltration efforts, official figures show.

China claims Taiwan as part of its territory and has threatened to use force to bring it under its control.

Taiwan says China also uses "grey zone" tactics, including espionage, cyberattacks and disinformation, to weaken its defences.

Lai said that there would a review and an amendment to the law "to reinstate the military trial system", he told reporters after a national security meeting.

"Military judges will return to the front line," Lai said.

He said military judges would work "alongside prosecutorial and judicial agencies to handle criminal cases involving active-duty military personnel accused of treason, aiding the enemy, leaking classified information, dereliction of duty, insubordination, and other military offences".

Taiwan's intelligence agency has said previously that 64 people were prosecuted for Chinese espionage in 2024, compared with 48 in 2023, and 10 in 2022.

Retired and serving members of the military were the main targets of China's infiltration efforts, Taiwan's National Security Bureau said.

Taiwan disbanded the military court system after the death of a young corporal in 2013.

Hung Chung-chiu died of heatstroke apparently after being forced to exercise excessively as punishment for taking a smartphone onto his base -- just days before the end of his compulsory year-long military service.

Both sides of the Taiwan Strait have been spying on each other for decades.

But analysts have warned that espionage is a bigger problem for Taiwan, which faces the existential threat of a Chinese invasion.

In recent years, China has ramped the deployment of fighter jets and warships around the island, and sought to erase Taiwan from the international stage by poaching its diplomatic allies and blocking it from global forums.