China has told Japan that it intends to replace its ambassador to Japan, Cheng Yonghua, early next month, ending what has been an unusually long stint for a Chinese envoy in Tokyo, sources familiar with bilateral ties said Wednesday.

With relations between the two countries improving, Beijing has likely deemed it is in a position to send a new ambassador, the sources said. Vice Foreign Minister Kong Xuanyou, considered an expert on Japan, is seen as a leading candidate to succeed Cheng.

News of the impending replacement comes amid expectations that Chinese President Xi Jinping will visit Japan in July, when the nation hosts the Group of 20 summit in Osaka. It would be Xi's first trip to Japan since he came to power in 2013.