BEIJING, March 19 (Xinhua) -- Chinese mainland officials Monday expressed condolences over the passing of writer Li Ao in Taiwan.

"We are saddened to hear of the passing of Li and express our sincere condolences to his family," Zhang Zhijun, director of the Taiwan Affairs Office of the State Council, said in a message to Li's family.

Li exhibited strong nationalist feelings, upheld national reunification, opposed "Taiwan independence," promoted Chinese culture and devoted himself to cross-Strait exchanges, Zhang said.

Chen Deming, president of the mainland-based Association for Relations Across the Taiwan Strait, also sent a message of condolence to Li's family, praising the writer's efforts to promote Chinese culture, support China's reunification and boost cross-Strait exchanges.

Li, who had suffered from brain tumor since July 2015, died Sunday at the age of 83.