After days of speculation, it has been confirmed that North Korea’s leader Kim Jong-un has visited China.
Rumours circulated earlier this week after reports a high-profile figure had arrived on a special train, similar to that used by Mr Kim’s father.
The visit, confirmed by China and North Korea, was Mr Kim’s first known foreign trip since taking office in 2011.
Mr Kim held “successful talks” with the Chinese leader Xi Jinping in Beijing, China’s Xinhua news agency reports.
The visit is considered a significant step in North Korea’s preparation for agreed talks with South Korea and the United States. Mr Kim is due to meet President Donald Trump in May.
Analysts had predicted North Korean and Chinese leaders would be likely to meet before that summit goes ahead.
During the unofficial visit, Xinhua said Mr Kim assured his Chinese counterpart he is committed to denuclearisation.
“The issue of denuclearisation of the Korean Peninsula can be resolved, if South Korea and the United States respond to our efforts with goodwill, create an atmosphere of peace and stability while taking progressive and synchronous measures for the realisation of peace,” Kim was reported saying.
North Korea’s nuclear and missile programme is at the heart of the recent spike in tension with the US.
North Korea’s KCNA news agency called the visit “a milestone” in improving bilateral ties with China – North Korea’s main ally.
It also said Mr Xi had accepted an invitation to return the visit.
Mr Kim visited with his wife, Ri Sol Ju, from Sunday to Wednesday, according to reports.
The trip is the latest in a flurry of diplomatic activity in recent weeks after ties between North and South Korea began improving at the start of the year and during the Winter Olympics in South Korea.
Last month, Mr Trump accepted an unprecedented invitation to meet Mr Kim, after months of hostility and North Korean missile tests.
If the summit goes ahead, Mr Trump would become the first sitting US President to ever meet a North Korean leader.