A North Korea's Air Koryo plane landed in an airport in Dalian, China on Tuesday.
Chinese president Xi Jinping has met North Korean leader Kim Jong Un in a northern Chinese port city, officials said.
The meeting, held over Monday and Tuesday in Dalian, is the second between the two men in recent weeks following Mr Kim's visit to Beijing in March, his first since taking power six years ago.
China is North Korea's only major ally, although trade between them has plummeted in recent months as Beijing enforces United Nations economic sanctions in response to the North's nuclear and ballistic missile tests.
The meeting between the two leaders comes as Mr Kim prepares to hold a historic summit with US president Donald Trump.
China has been eager to assert its importance in the process of lowering tensions on the Korean Peninsula.