The world will be watching as Donald Trump and Kim Jong-un step into Singapore’s luxurious Capella Hotel on Tuesday morning for a historic meeting that few would have imagined possible just a few months ago.

The summit, which will mark the first time a sitting US president has met with the leader of North Korea, is set to rank among the most extraordinary tête-à-têtes between world leaders in modern times.

In terms of symbolism alone, it deserves mention alongside historic Cold War moments such as Richard Nixon’s meeting with Chairman Mao in Beijing and Ronald Reagan’s outreach to Soviet leader Mikhail Gorbachev.

It’s all the more remarkable when you remember that just a few months ago Mr Trump was taunting Mr Kim as “little rocket man,” while North Korean state media referred to the US President as a “deranged dotard”.

When Trump and Kim finally come face to face about 9am (local time) on Tuesday on the neutral ground of Singapore, North Korea’s nuclear weapons, a source of growing anxiety around the world, will be at the top of the agenda.

Washington and the bulk of the international community want Pyongyang to commit to complete and verifiable denuclearisation, which would include permitting international inspectors inside the secretive country.

Since 2006, Pyongyang has carried out six successful nuclear tests and numerous missile launches that have attracted international sanctions and censure.

Many experts believe the regime’s capabilities have recently advanced to the point where it could strike the US mainland — and far-flung allies such as Australia — with a nuclear-armed ballistic missile.

For both leaders, the summit may itself be a victory. Photo: Getty

In return for any commitment to nuclear disarmament, Mr Kim is likely to expect relief from punishing US and UN sanctions, and a guarantee that his heredity leadership will not be threatened by outside force or interference.

Other sweeteners could include diplomatic recognition by Washington and a peace treaty to formally end the Korean War, which left North and South Korea locked in a technical state of war that remains unresolved to this day.

Striking a conciliatory tone on Monday, the regime-run Rodong Sinmun newspaper said the talks would focus on working toward a “permanent and peaceful regime in the Korean peninsula” and “the denuclearisation of the Korean peninsula”.

Mr Trump sounded a similarly hopeful note on Twitter, announcing there was “excitement in the air!” in Singapore.

Mr Kim left his luxurious hotel for a late-night city tour of Singapore on Monday night, visiting the Flower Dome at Gardens by the Bay with Singaporean Foreign Minister Vivian Balakrishnan.

The foreign minister posted to Facebook a breezy selfie (“Guess where?”) of him and a smiling Mr Kim as some experts suggest the tour could mean that North Korea and the US have narrowed their differences ahead of the summit. 

Despite the anticipation and historical weight of the moment, there’s widespread scepticism this pair of unlikely diplomats will be able to forge a lasting breakthrough.

Many observers consider it inconceivable that Mr Kim, who took power following the death of his father in 2011, would ever relinquish a nuclear arsenal that serves as the ultimate deterrent to outside intervention and an invaluable bargaining chip on the international stage.

Leaks from preparatory talks between US and North Korean officials this week have indicated the two sides have yet to even reach a shared understanding of what denuclearisation would entail.

“I think we need to have realistic expectations, and be prepared for both positive and negative developments, whether in the short or long term,” Daniel Pinkston, a former Korean linguist in the US Air Force, told The New Daily.

“There is no sign to indicate North Korea will denuclearise unless it’s part of global denuclearisation. Everything they say indicates they will denuclearise when everyone else does.

“Until then, they say their nuclear arsenal provides security, peace and stability.”

Even if Pyongyang does agree to comprehensive disarmament, verification and enforcement would remain as major challenges.

No one knows how many nuclear weapons the reclusive country actually possesses. Even if they were let into the country, inspectors would have to contend with the possibility that any number of illicit devices or sites could exist out of sight inside a vast network of underground tunnels.

On top of all that, North Korea has a long history of reneging on agreements to rein in its provocative behaviour.

Known to take pride in ripping up the rulebook, Mr Trump may be tempted to announce a historic-sounding deal with Mr Kim irrespective of any fine print that might make an enduring resolution unlikely. By coming this far, he has already proved to be a trailblazer compared to his predecessors, with whom he never ceases to compare himself favourably.

For Mr Kim, too, the summit is attractive for reasons that don’t depend on any tangible outcome. Observers widely agree a meeting with the US President offers Mr Kim an unprecedented opportunity to boost his legitimacy at home and abroad.

“His father or even grandfather did not have that kind of chance,” Uk Yang, an advisor to South Korea’s Ministry of National Defence, told The New Daily.

“So the meeting itself is a key political victory for North Korea, especially for Kim Jong-un.”