North Korea's second most senior leader, Kim Yong-nam, is in China for a rare visit expected to focus on the North's nuclear programme.
Kim Yong-nam formally heads North Korea's parliament
His visit comes amid a flurry of efforts to restart stalled six-party talks aimed at addressing the crisis.
US Secretary of State Colin Powell is to visit Japan, China and South Korea for talks on the issue later this week.
But analysts believe there is unlikely to be much progress before the US presidential election in November.
The six-party talks were launched last August with great fanfare, but more than a year on this process has stalled.
The fourth round of talks had been scheduled for September but North Korea boycotted the meeting, citing as reasons South Korea's controversial nuclear experiments and what Pyongyang called Washington's "hostile policy" towards it.
A BBC correspondent in Beijing, Louisa Lim, says China's leaders will be pushing Mr Kim to return to the negotiating table.
China is the North's main ally and its biggest aid donor, although it says it has limited influence over the North Korean leadership.
There is speculation that Pyongyang also wants to wait and see who will win the US presidential election.
President George's Bush challenger, John Kerry, has a very different approach to the North Korean nuclear crisis - advocating bilateral talks rather than just the six-party approach.
During his three-day visit, Mr Kim is also scheduled to visit a science park in Beijing. Western diplomats say economic reform will also be high on the agenda, amid concerns that Pyongyang is not wholly committed to pushing forward its reform process.