North Korean leader Kim Jong Un, left, prepares to shake hands with South Korean President Moon Jae-in at the border village of Panmunjom in Demilitarized Zone Friday, April 27, 2018. Their discussions will be expected to focus on whether the North can be persuaded to give up its nuclear bombs. (Korea Summit Press Pool via AP)

GOYANG, South Korea — The leaders of North and South Korea on Friday pledged to work toward their common goal of denuclearizing their peninsula, following a historic day of talks on the border that has divided them for almost seven decades.

It was a day marked by an astonishing level of congeniality between the two — including a warm embrace at the signing concluding the talks — but was short on details as to what, exactly, “denuclearization” means for each of them.

Still, the fact that Kim Jong Un and Moon Jae-in spent so much time together and came up with a joint statement marks progress after a year of threats and missile launches that brought the specter of war back to the Korean Peninsula.

“This provides the political space for Trump to have his own summit with Kim,” said Duyeon Kim, a fellow at the Korean Peninsula Future Forum. “Whether or not Kim Jong Un can be believed is a completely different story.”

Moon and Kim spent hours together on Friday, both in formal talks and in a private discussion on park benches outside in the sun, surrounded by birdsong.

Afterward, they returned to the Peace House building on the southern side of the border and issued a joint statement in which they identified as their joint goal making the Korean Peninsula nuclear free “through complete denuclearization.”

This phrase that will ring alarm bells in Washington because it implies that nuclear weapons will not be allowed in South Korea either.

The United States, South Korea’s security ally, regularly sends nuclear-capable aircraft and ships to the South during military exercises, so this clause will raise suspicions that North Korea is calling for the end of the U.S.-South Korea alliance.

Kim and Moon also agreed to work to turn the armistice agreement that ended the Korean War in 1953 into a peace treaty that would officially bring the war to a close. The United States signed the armistice agreement on behalf of the South Korean side, and Trump has said that he supports such a move.

The two sides will set up a Korean liaison office to be established in Kaesong, a city just over the Northern side of the border, and Moon said he would visit Pyongyang this fall.

The warmth of the meeting and the positive, if vague, signals now set the stage for Kim to meet with President Donald Trump at the end of May or beginning of June. Trump has said he will only go to the talks if they promise to be “fruitful,” a bar that is likely to have been met with Friday’s meetings.

The White House welcomed Friday’s summit as it started.

“We wish the Korean people well,” press secretary Sarah Huckabee Sanders said in a statement.

“We are hopeful that talks will achieve progress toward a future of peace and prosperity for the entire Korean Peninsula,” she said, adding that the White House hoped the “robust discussions” would pave the way for the planned meeting between Trump and Kim.

When Kim on Friday morning crossed the line that has divided the Korean Peninsula for 65 years, it was the first time since the Korean War halted in 1953 that a North Korean leader has come to South Korea, and it was broadcast live across the country, with commuters stopping in train stations and teachers stopping classes so their students could watch the moment.

This is only the third inter-Korean summit and is the first that South Korea has hosted.

The South Korean president at the time, Kim Dae-jung, went to Pyongyang in 2000 to meet then-leader Kim Jong Il, the current leader’s father, and was awarded the Nobel Peace Prize for his efforts. However, the shine came off when it emerged the South had paid the North $500 million to participate.

Roh Moo-hyun, Kim Dae-jung’s successor, followed suit by traveling to Pyongyang in 2007 and also meeting Kim Jong Il. At the time, Moon was Roh’s chief of staff and head of the summit preparation committee.