Taiwan’s ground and air forces have conducted a drill, with the self-ruled island’s president Tsai Ing-wen and Paraguayan President Mario Abdo Benitez attending the military exercises.

Taiwan’s defense ministry spokesman Chen Chung-chi said the Tuesday drill demonstrated the combat readiness and efficacy of the Taiwanese military.

Taiwanese forces fought back a “simulated invasion by [an] opposing force” near the northern city of Taoyuan during the drill.

The military drill comes amid tensions between Taiwan and China, which has warned that it will defend — by force if necessary — its “One China” principle under which the self-ruling island is regarded as part of Chinese territory, pending reunification.

Most world countries adhere to that policy.

Paraguay’s visiting President Mario Abdo Benitez attended the drill along with the island’s president Tsai Ing-wen.

Chung-Chi told media that the drill would also have a positive effect on future exchanges between Taiwan and Paraguay.

Tsai paid a visit to Paraguay and Belize in August to boost ties with the only two Latin American nations that maintain ties with Taipei. Only 17 countries worldwide still maintain diplomatic ties with Taiwan.