BEIJING -- A senior Taiwan affairs official on Saturday asked researchers on the Chinese mainland to carry out in-depth investigation and research on major and tough issues in Taiwan-related work and offer their advice to authorities.

Zhang Zhijun, director of the Taiwan Affairs Office of the State Council, made the remarks at a meeting of part-time researchers of the Research Center of Cross-Straits Relations in Beijing.

"Since the 18th National Congress of the Communist Party of China (CPC) in 2012, work related to Taiwan has withstood major tests and achieved vital progress," he said, adding that the progress has been made thanks to the leadership of the CPC Central Committee.