SEOUL/HANOI • North Korea warned US President Donald Trump yesterday not to listen to US critics who were disrupting efforts to improve ties, as its leader, Mr Kim Jong Un, made his way across China by train to a second summit with Mr Trump in Vietnam.

The two leaders will meet in Hanoi on Wednesday and Thursday, eight months after their historic summit in Singapore, the first between a sitting United States president and a North Korean leader, where they pledged to work towards the complete denuclearisation of the Korean peninsula.

But their vaguely worded agreement has produced few results and US Democratic senators and US security officials have warned Mr Trump against cutting a deal that would do little to curb North Korea's nuclear ambitions.

The North's KCNA state news agency said such opposition was aimed at derailing the talks. "If the present US administration reads others' faces, lending an ear to others, it may face the shattered dream of the improvement of the relations with the DPRK and world peace and miss the rare historic opportunity," the news agency said in a commentary, referring to North Korea by the initials of its official name, the Democratic People's Republic of Korea.

The Trump administration has pressed the North to give up its nuclear weapons programme, which, combined with its missile capabilities, poses a threat to the US, before it can expect any concessions.

In a series of tweets yesterday on the eve of his departure for the summit, Mr Trump said North Korea could become one of the world's "great economic powers" if it relinquished its nuclear arsenal.

"Chairman Kim realises, perhaps better than anyone else, that without nuclear weapons, his country could fast become one of the great economic powers anywhere in the world," he wrote.

Mr Trump said he and Mr Kim both expect a continuation of the progress made at the first summit in Singapore. He also praised China and Russia for enforcing sanctions on North Korea, while insisting that he had a "great relationship with Mr Kim". "The last thing China wants are large-scale nuclear weapons right next door. Sanctions placed on the border by China and Russia have been very helpful."

Mr Trump has previously said he had no pressing schedule for North Korea's denuclearisation, hinting at a more gradual, reciprocal approach, long favoured by Pyongyang.

In a letter to Mr Trump last week, three Democratic chairmen of key House committees accused the administration of withholding information on the negotiations with North Korea. "There are ample reasons to be sceptical that Chairman Kim is committed to a nuclear-free North Korea," the lawmakers wrote.

US intelligence officials also recently testified to Congress that North Korea was unlikely to ever give up its entire nuclear arsenal.

KCNA, referring to US fears of the North's weapons, said if this week's talks ended without results, "the US people will never be cleared of the security threats that threw them into panic".

While few details of Mr Kim's trip have been announced, North Korea's state media has confirmed that Mr Kim left Pyongyang by train on Saturday afternoon for the summit.

In rare, revealing coverage of Mr Kim's travel while it is still going on, the North's Rodong Sinmun newspaper featured photographs of him getting a red-carpet send-off in Pyongyang and waving from a train carriage door while holding a cigarette. Mr Kim is being accompanied by senior North Korean officials as well as his influential sister on the trip.

REUTERS, AGENCE FRANCE-PRESSE