By Christine Kim and Josh Smith
SEOUL (Reuters) - The leaders of the two Koreas made their way to the heavily fortified demilitarised zone between the countries early on Friday, seeking to end their decades-long conflict and ease tensions over the North's nuclear weapons programme.
South Korea's Moon Jae-in will greet North Korean leader Kim Jong Un at the military demarcation line at 9:30 a.m. (0030 GMT), making Kim the first North Korean leader to set foot in the South since the 1950-53 Korean War.
The two are expected to talk denuclearisation and exchanges between the Koreas and also will plant a memorial tree at the border truce village of Panmunjom as part of the first inter-Korean summit in more than a decade.
Friday's summit will set the stage for Kim to meet with U.S. President Donald Trump in late May or early June, in what would be an unprecedented first encounter between sitting leaders of the two countries.
Just months ago, Trump and Kim were trading threats and insults as North Korea's rapid advances in pursuit of nuclear-armed missiles capable of hitting the United States raised fears of a fresh conflict on the Korean peninsula.
North Korea's official KCNA news agency said Kim had left Pyongyang for the "historical" summit in which he would "open-heartedly discuss with Moon Jae-in all the issues arising in improving inter-Korean relations and achieving peace, prosperity and reunification of the Korean peninsula."
Just days before the summit, Kim said North Korea would suspend nuclear and long-range missile tests and dismantle its only known nuclear test site.
Moon was also seen leaving the presidential office in a bulletproof sedan. He stopped briefly to greet dozens of summit supporters waving South Korean flags near the Blue House.
Hundreds of demonstrators were seen gathering in downtown Seoul from early morning to protest or support the summit.
Scepticism has been rampant about whether Kim is ready to abandon the hard-earned nuclear arsenal his country has defended and developed for decades as what it says is a necessary deterrent against U.S. invasion.
The two neighbours expect to release a joint statement late on Friday - possibly called the Panmunjom Declaration - that could address denuclearisation and peace, and an improvement in relations, South Korean officials said.
Impoverished North Korea and the rich, democratic South are technically still at war because the Korean War ended in a truce, not a peace treaty.
The United States stations 28,500 troops in South Korea as a legacy of the Cold War conflict, which pitted the South, the United States and United Nations forces against the communist North, backed by China and Russia.
On Thursday, Trump said he was considering three or four dates as well as five locations for his meeting with Kim, although once again he added that it remained unclear whether the meeting will occur.
"It could be that I walk out quickly - with respect - but ... it could be that maybe the meeting doesn't even take place," he told Fox News by telephone. "Who knows. But I can tell you right now they want to meet."
The White House released two photographs of then Secretary of State-designate and CIA chief Mike Pompeo's meeting with Kim in North Korea over the Easter weekend to discuss the planned summit. It was Kim's first known meeting with a U.S. official.
The photos show Kim and Pompeo, who was confirmed as secretary of state on Thursday, shaking hands. In one they faced each other looking serious; in the other they both appeared to wear faint smiles. https://bit.ly/2KfRHN3
The latest summit has particular significance not least because of its venue: the Demilitarised Zone, a 160-mile (260-km) long, 2.5-mile (4-km) wide strip of land created in the 1953 armistice to serve as a buffer between the South and North.
For the first time, key moments such as Kim crossing the border into the South, the two leaders shaking hands and walking to the Peace House for their talks, will be broadcast live.
PRELUDE TO TRUMP SUMMIT
Moon, who took office in May pledging to restore ties with the North and who has tirelessly called for dialogue, helped steer Kim and Trump towards meeting, a major coup for the liberal president.
After dozens of missile launches last year, Kim embarked on a diplomatic offensive at the beginning of the year. Kim sent a delegation to the Winter Olympics in South Korea in February before Trump stunned the world by agreeing to meet Kim to discuss "denuclearisation" of the Korean peninsula.
Now comes the hard part.
The history of failed nuclear negotiations with Pyongyang has made many U.S. officials sceptical of Kim's true intentions and suspicious of his recent overtures as more of a bid to win relief from wide-ranging U.N. sanctions and to divide Washington and its allies.
There is also concern that North Korea could insist on taking incremental steps in return for simultaneous incentives from Washington, the kind of a phased approach that U.S. officials have rejected.
(Reporting by Christine Kim and Josh Smith in SEOUL; Additional reporting by David Brunnstrom and Susan Heavey and Eric Beech in WASHINGTON; Editing by Lincoln Feast and James Dalgleish)