Chinese President Xi Jinping will travel to North Korea on Thursday for a two-day visit, state media report.
Mr Xi will meet North Korean leader Kim Jong-un to discuss the problems facing the Korean peninsula.
The two-day visit will be the first by any Chinese leader to North Korea in 14 years, and Mr Xi’s first since taking power in 2012.
It comes a week before the G-20 summit in Japan, at which Mr Xi is expected to meet US President Donald Trump.
Mr Kim has visited China four times, but no Chinese president has visited Pyongyang since Hu Jintao was hosted by Mr Kim’s father Kim Jong-il, in 2005.
The visits were intended to help relations between the two countries after Beijing backed a series of UN sanctions against North Korea over its nuclear activities.
“China-DPRK relations have opened a new chapter,” state television CCTV said, adding that Mr Xi and Mr Kim have reached a “series of important consensus” (sic) in past meetings.
Talks between the US and North Korea have stalled over the issue of North Korea’s nuclear programme, despite two meetings between Mr Trump and Mr Kim.
The US and China are currently locked in an escalating trade war, with both countries announcing new tariffs on each other’s goods.
South Korea’s presidency said it hoped the visit would contribute to the resumption of talks over denuclearisation.
What happened at the last visit?
Beijing has considerable political influence in Pyongyang. The relationship is one that Chinese leader Mao Zedong once called “as close as lips and teeth”.
As part of a three-day trip to Pyongyang in 2005, Mr Hu was greeted by North Korean leader Kim Jong-il at Pyongyang airport.
Thousands of North Koreans staged a carefully choreographed welcome as his motorcade headed into the capital and a banquet was hosted in his honour.
Mr Kim praised China’s diplomatic efforts and promised the Chinese president that Pyongyang would take part in nuclear talks.
Mr Hu and Kim Jong-il continued to meet in Beijing after this visit.