Xinhua, the official Chinese news agency, confirmed Kim’s visit after a flurry of reports from South Korean media that a train appearing to be carrying a senior North Korean official had passed through Dandong, a Chinese city on the border with North Korea. The train was expected to pull into Beijing on Tuesday morning, the South Korean news agency Yonhap reported, citing an anonymous source.

North Korea’s state-run Central Television also confirmed the visit, reporting that Kim started the four-day visit Monday at Xi’s invitation. It said he was accompanied by his wife, Ri Sol Ju, and senior officials, including Kim Yong Chol, Kim’s right-hand man in diplomatic negotiations with the United States and South Korea.

The visit by Kim suggests that he is seeking Xi’s advice or highlighting his country’s alliance with China as he prepares for another meeting with Trump. The brief report by Xinhua gave no details of who Kim will meet in China. But his visit, scheduled to end Thursday, will allow plenty of time to consult with Xi and other senior Chinese leaders.

Kim visited China three times last year to meet with Xi before and after his first meeting with Trump, in Singapore last June.