WASHINGTON (AFP) - A senior North Korean official was bound for New York for high-level talks with US officials on Tuesday (May 30) as preparations for a historic nuclear summit between Donald Trump and Kim Jong Un gathered pace.

General Kim Yong Chol, vice chairman of the central committee of the Workers' Party and right hand man to Kim, will meet US Secretary of State Mike Pompeo in New York "later this week," the White House said.

Trump confirmed the general was on his way in a tweet and boasted that Washington would have a "great team" for the talks on resolving the old foes' nuclear stand-off, which he still hopes will take place on June 12 in Singapore.

"Meetings are currently taking place concerning Summit, and more. Kim Young Chol, the Vice Chairman of North Korea, heading now to New York. Solid response to my letter, thank you!" Trump wrote.

Trump will also meet Japan's Prime Minister Shinzo Abe in Washington on June 7, White House spokesman Sarah Sanders said.

"Since the President's May 24 letter to North Korean leader Kim Jong Un, the North Koreans have been engaging," she said. "The United States continues to actively prepare for President Trump's expected summit with leader Kim in Singapore."

A spokesman for the North Korean mission to the United Nations said he was unable to confirm that the general was on his way to New York but added that "preparation for the summit is proceeding at the highest level." The North Korean envoy landed at Beijing airport on Tuesday and was to meet with Chinese officials before travelling on to the United States on Wednesday, according to South Korea's Yonhap news agency.

The trip is part of a flurry of diplomacy before the on-again, off-again summit.

TRUCE VILLAGE

Trump briefly cancelled the talks last week, citing "open hostility" from the North, but since then both sides have dialled down the rhetoric and the process appears to be back on track.

On Sunday, US negotiators, headed by Washington's ambassador to the Philippines Sung Kim, began meeting North Korean counterparts in the truce village of Panmunjom that divides the two Koreas. "They plan to have additional meetings this week," Sanders said.

"Separately, Joe Hagin, White House Deputy Chief of Staff, and the US pre-advance team are in Singapore coordinating the logistics of the expected summit."

Chung Sung Yoon, an analyst at the Korea Institute for National Unification, said Kim Yong Chol would be the most senior North Korean on US soil since Vice Marshal Jo Myong Rok met then president Bill Clinton in 2000.

The general has played a front-seat role during recent rounds of diplomacy aimed at ending the nuclear stalemate on the Korean peninsula.

He sat next to Trump's daughter Ivanka, who is also a White House aide, during February's closing ceremony for the Winter Olympics in South Korea, an event that was seen as a turning point in the nuclear crisis.

He also accompanied Kim Jong Un on both of his recent trips to China to meet President Xi Jinping, and held talks with Pompeo when he travelled to Pyongyang.

YAWNING GAP

General Kim is a notorious figure in South Korea, where he is blamed for masterminding the 2010 sinking of the navy corvette the Cheonan, which killed 46 sailors, an attack for which North Korea denies responsibility.

From 2009 to 2016 he was also director of North Korea's General Reconnaissance Bureau, the unit tasked with cyber warfare and intelligence gathering.

During that period North Korea ramped up its hacking programs, including a hugely costly penetration of Sony Pictures.

His journey to the US caps a frenetic few days of meetings between North Korean and American officials.

Japanese broadcaster NHK showed footage of Kim Chang Son, Kim Jong Un's de facto chief of staff, arriving in Singapore on Monday, escorted by three bodyguards.

An AFP photographer saw Kim entering Singapore's luxury Fullerton hotel Tuesday and leaving some 30 minutes later in a three-vehicle convoy.

If the June 12 date stands, officials have only a fortnight to finalise details such as where in Singapore the talks will take place and how internationally sanctioned North Korean officials will travel there.

The key task is to settle the agenda.

The main stumbling block is likely to be the concept of "denuclearisation" - both sides say they want it, but there is a yawning gap between their definitions.

Washington wants North Korea to quickly give up all its nuclear weapons in a verifiable way in return for sanctions and economic relief.

But analysts believe North Korea will be unwilling to cede its nuclear deterrent unless it is given security guarantees that the US will not try to topple the regime.