Hard choices for US, N. Korea at talks!

• North Korea and the United States may sign a peace deal that could pave the way for a cautious thaw in ties.

After a burst of hectic diplomacy, Donald Trump and Kim Jong Un's nuclear summit is on course to go ahead - but if it is to live up to the hype, both sides will need to make difficult concessions.

In what would be the first breakthrough in the fraught process, North Korea and the United States may sign a peace deal that could pave the way for a cautious thaw in ties."Can you believe that we're talking about the ending of the Korean War?" Trump asked rhetorically, marveling at his own diplomatic audacity. The two countries have been technically at war for decades, even if their conflict was frozen by an armistice 65 years ago.

But what Washington is really seeking is the North's nuclear disarmament.

Pyongyang, however, has long insisted on becoming a respected nuclear state and - while it may have suspended nuclear and missile tests - surrendering its bombs is off the table.

So how can the circle be squared? How can the two parties arrive at what Washington says must be the "complete, verifiable and irreversible" denuclearization of the Korean peninsula?

Many are skeptical.

"We'll know right away if it's a failure," Center for Strategic and International Studies analyst Boris Toucas told reporters.

"For example, if Kim won't give written guarantees on denuclearization or if there's just a declaration of good intent without a roadmap."

The summit would be a challenge for the most seasoned diplomats and just last year neophyte statesman Trump was mocking Kim as "Little Rocket Man," while the young autocrat sneered at the "mentally deranged dotard."

The stakes have been raised still further by the accelerated timeframe. Trump may have conceded there will be no grand deal at the first meeting, but he wants a win before his first term ends in 2021.

North Korean leaders have been seeking face-to-face talks with a sitting US president for a quarter of a century, but Trump only agreed to meet Kim in March and now seems to be in a hurry.

So much of a hurry, in fact, that many in Washington worry he will naively make concessions without securing the North Korean arsenal.

But the cynics were also cheered that Trump now publicly accepts that the meeting is probably only the start of the process, and some former officials think some progress can be made.

Ambassador Joseph Yun was the US special representative for North Korea until days before Trump accepted the summit invitation, and is a veteran of backchannel talks.

He said that if the summit is to count as a success, both sides will have to make rapid concessions to build trust before a longer process leading to eventual disarmament and normalisation can begin.

"The basic proposition that the United States is trying to tell North Korea is: 'You are safer without nuclear weapons than with nuclear weapons,'" said Yun, now an advisor at the US Institute of Peace.

North Korean leaders have long assumed the opposite: Only with weapons can they secure the Kim dynasty's survival and become a respected nuclear power like India, at the diplomatic top table.

But certain security guarantees may convince Kim to follow the diplomatic path after the summit.

"One, I believe in this particular instance would require what I call an 'end of war declaration,' that the Korean War, which technically ended with an armistice in 1953, is over," Yun said.