North Korean leader Kim Jong Un may visit China as early as Tuesday to brief President Xi Jinping on last week's summit with US President Donald Trump, according to Japanese reports.
Kim is expected to fly into Beijing and security preparations are already under way, Japan's Nikkei business daily quoted sources familiar with the matter as saying.
If confirmed, it would mark the third time Kim has visited China since March, when he made his inaugural foreign trip as leader.
Citing diplomatic sources, Japanese news agency Kyodo said a "high-ranking North Korean official, possibly Kim" was due to visit Beijing by air.
Kyodo later reported that a North Korean freight plane used for the June 12 Singapore summit had arrived in Beijing.
An AFP reporter in Pyongyang said the only scheduled international flight -- an Air Koryo plane to Beijing -- had been briefly delayed for no reason, which often happens when Kim travels.
Kim is seeking relief from economic sanctions in return for his pledge to denuclearise and is believed to be seeking support from China for that, the Nikkei said in a dispatch from Beijing.
Following the historic US-North Korea summit in Singapore a week ago, China suggested the UN Security Council could consider easing the economic punishment of its Cold War-era ally.
China was not a direct player in the negotiations in Singapore but retains strong influence behind the scenes.
US Secretary of State Mike Pompeo rushed to the Chinese capital to brief Xi and other top leaders soon after the Trump-Kim meeting.
In a joint statement following the Singapore meeting, Kim pledged to "work toward the complete denuclearisation of the Korean Peninsula."
Trump hailed this as a concession but critics said the stock phrase long used by Pyongyang stopped short of longstanding US demands for North Korea to give up its atomic arsenal in a "verifiable" and "irreversible" way.
In return, Trump said he would stop joint military drills with South Korea, long seen as a provocation by Pyongyang and Beijing.
On Tuesday, the US and South Korean militaries confirmed they have called off upcoming joint exercises following Trump's order.