Taiwan President Tsai Ing-wen has reviewed a military unit before her trip to Central America that includes transits in the United States.

Tsai visited an army engineering unit in the southern city of Chiayi on Saturday.

She saw troops erect anti-tank barriers and practice martial arts.

Tsai told the soldiers that protecting Taiwan and defending democracy has always been the military's most important mission. She also said she believes that "only by continuously training and strengthening the military's war preparedness," can it be "even more able to protect our home and defend our country."

Tsai is scheduled to leave for two Central American countries on Wednesday. She is expected to meet with US House Speaker Kevin McCarthy during a stopover in the United States.

In August last year, China responded with massive military exercises when then US House Speaker Nancy Pelosi visited Taiwan.

Concerns are rising that China could make threatening moves to coincide with Tsai's upcoming trip.

Taiwan authorities say Tsai's review of the military unit was decided one day after the itinerary of her trip abroad was announced.

Observers say the inspection was intended to demonstrate Taiwan's readiness to respond to any threat from China.