By Faith Hung KAOHSIUNG Taiwan (Reuters) - China's top official in charge of relations with self-ruled Taiwan said on Friday that he understood and respected the choices of the island's people, as he was met by noisy protests in the traditionally anti-China far south of Taiwan. Zhang Zhijun, director of China's Taiwan Affairs Office, is making the first trip ever by the head of the body to Taiwan, a visit marked by a highly unusual meeting with an opposition party stalwart and mayor of the pro-independence southern port of Kaohsiung, Chen Chu. Protesters waved placards deriding Zhang as a "communist bandit". While Chen has previously visited China and met Zhang there, spearheading efforts by the Democratic Progressive Party to engage with Beijing, such high-level meetings in Taiwan with opposition figures are almost unheard of.