Donald Trump dined with dictator Kim Jong Un on Wednesday night in Hanoi, Vietnam, painting a rosy picture for economic prosperity in North Korea after previously claiming the brutal regime is no longer a nuclear threat to the United States.

There’s just one problem: intelligence experts say the North has only sought to advance its nuclear ambitions under Mr Trump, who has “undermined his negotiators routinely” throughout behind-the-scenes conversations ahead of this week’s summit.

“North Korea's nuclear and missile capabilities are more dangerous than when Trump took office and remain a strategic threat to America’s allies in the region,” Jon Wolfsthal, former senior director for arms control and nonproliferation at the National Security Council under Barack Obama, told The Independent.

“A lack of testing by North Korea has had almost no impact on that threat,” he added.

Mr Trump has touted an apparent calming of tensions with North Korea during his presidency and a lack of missile testing as signs the reclusive regime could be willing to forego its efforts of obtaining an intercontinental missile capable of reaching mainland US.

On Wednesday, Mr Trump repeated his claims that North Korea could become on the world’s “great economic powers” during his face-to-face summit with the regime leader, saying in front of reporters, “I think that your country has tremendous economic potential. Unbelievable. Unlimited. And I think that you will have a tremendous future … I look forward to watching it happen, and helping it to happen.”

The president also took a shot at Democrats and his predecessor on Twitter, writing, “The Democrats should stop talking about what I should do with North Korea and ask themselves instead why they didn’t do ‘it’ during eight years of the Obama Administration?”

“Vietnam is thriving like few places on earth. North Korea would be the same, and very quickly, if it would denuclearize,” he tweeted. “The potential is AWESOME, a great opportunity, like almost none other in history, for my friend Kim Jong Un. We will know fairly soon - Very Interesting!”

In speaking to The Independent, Mr Wolfsthal acknowledged shortcomings by the previous administration in achieving the denuclearisation of North Korea.

Trump and Kim: leaders arrive in Vietnam for talks Show all 7 1 /7 Trump and Kim: leaders arrive in Vietnam for talks Trump and Kim: leaders arrive in Vietnam for talks Donald Trump and Vietnamese President Nguyen Phu Trong make their way to a meeting at the Presidential Palace in Hanoi Reuters Trump and Kim: leaders arrive in Vietnam for talks Donald Trump waves a Vietnamese flag as Vietnam's Prime Minister Nguyen Xuan Phuc looks on AFP/Getty Trump and Kim: leaders arrive in Vietnam for talks Donald Trump waves as he leaves the Presidential Palace in Hanoi AFP/Getty Trump and Kim: leaders arrive in Vietnam for talks North Korean leader Kim Jong-un, right, is welcomed on his arrival at the Melia Hotel in Hanoi AP Trump and Kim: leaders arrive in Vietnam for talks Kim Jong-un waves as he arrives by train in the Vietnamese border town of Dong Dang AP Trump and Kim: leaders arrive in Vietnam for talks North Korean leader Kim Jong-un receiving a situation report before the summit with Trump AFP/Getty Trump and Kim: leaders arrive in Vietnam for talks The motorcade carrying U.S President Donald Trump drives past Ho Chi Minh Mausoleum AP

Still, he noted the supposed difference between past efforts and what Mr Trump has seemingly employed throughout his two public spectacles in meeting with Mr Kim.

“Under Obama, we sought real progress, not the appearance of progress,” he said. “We did not succeed, but we remained steadfast and did not give away key steps North Korea has wanted for years.”

Mr Trump’s willingness to claim North Korea was no longer a threat made it “less likely that lower level North Koreans would engage with their US counterparts,” according to Mr Wolfsthal, who now serves as the director of the nuclear crisis group at Global Zero, a coalition of 300 world leaders seeking to eradicate nuclear arsenals globally.

Even Mr Trump's own Secretary of State Mike Pompeo contradicted the president, saying the North was still a threat in an interview with CNN ahead of the summit.

A major question remains surrounding Mr Trump’s second summit with the North Korean leader about what exactly his administration hopes to accomplish during the historic event. Whereas the North has sought a peace declaration that would effectively end the longstanding Korean War — Mr Trump said “We’ll see” about that happening before the two sat down for nuclear talks on Wednesday — the US has sought verifiable evidence of the North’s denuclearisation.

“Trump claimed in the campaign that only he can solve problems,” he added. “It is ridiculous to think that any President would work out the meticulous details needed to achieve and verify destruction of North Korean weapons.”

Support free-thinking journalism and attend Independent events

On Wednesday, the North Korean leader described his regime as “misunderstood,” without directly indicating whether it would work towards complete denuclearisation.