A South Korean delegation left for North Korea on Wednesday to attend a groundbreaking ceremony for reconnecting roads and railways across the divided peninsula despite stalled denuclearisation talks.
A nine-car special train carrying some 100 South Koreans, including officials and five people born in the North, was seen leaving Seoul railway station early in the morning for a two-hour journey to the North's border city of Kaesong.
Concerns arose that the train and other materials being brought into the North for the ceremony could breach various sanctions imposed on the isolated regime over its nuclear weapons programme, but the UN Security Council reportedly granted a waver for the event.
Seoul stressed that the ceremony would not herald the start of actual work on reconnecting and modernising road and rail links between the two Koreas -- which remain technically at war after their 1950-53 conflict ended without a peace treaty.
The event is a mere "expression of a commitment" to the projects, a South Korean Unification Ministry spokesman said, adding that construction would depend on "progress on the North's denuclearisation and circumstances concerning sanctions." The two sides wrapped up their joint railway and road inspections for the projects this month.
South Korea has set aside some $620,000 for the endeavour.
Following a rapid rapprochement earlier this year that culminated in a historic summit between Donald Trump and Kim Jong Un, progress has stalled with both sides accusing each other of dragging their feet and acting in bad faith.
Critics say North Korea has made no concrete commitments and is unlikely to surrender its atomic arsenal, while Washington's policy of maintaining pressure through isolation and sanctions has left Pyongyang seething.
Trump said Monday that he was "looking forward" to his second summit with Kim, which Washington says may take place early next year.
He tweeted the statement after he was briefed by Stephen Biegun, the US special representative on North Korea, who wrapped up a three-day trip to Seoul on Saturday.
Biegun said last week the United States will be more lenient in enforcing its blanket ban on US citizens' travel to the totalitarian state when dealing with aid workers, a goodwill gesture as Trump seeks a fresh summit.
The Trump administration has generally refused to let US aid groups operate in North Korea, seeking to both maximise pressure on Pyongyang and ensure the safety of Americans.
Biegun also said in Seoul last week Washington was willing to discuss trust-building initiatives with Pyongyang.
Senior transport officials from Russia, China and Mongolia as well as several foreign ambassadors to South Korea will attend Wednesday's ceremony, the South's Unification Ministry said.