KAOHSIUNG, Taiwan (Reuters) — Taiwan President Tsai Ing-wen visited a low-key but critical maintenance base for fighter jet engines on Saturday, offering encouragement as the Chinese-claimed island’s armed forces strain in the face of repeated Chinese air force incursions.

This month alone, China’s drills have included its jets crossing the mid-line of the sensitive Taiwan Strait and exercising near the Taiwan-controlled Pratas Islands in the South China Sea.