In a statement released by his office, Moon praised the summit as a "great victory achieved by both the United States and the two Koreas."
"I would like to pay my respect to President Trump who achieved a feat that no one else has ever delivered," he said. "Chairman Kim Jong Un will also be remembered as a leader who made a historic moment by taking the first bold step toward the world."
His statement, however, was quick to raise the potential difficulties of the road ahead, reflecting Moon's view that the summit was but the first step in a years-long process to stabilize and denuclearize the Korean peninsula.
Moon has been a cautious but determined broker of peace between the two Koreas, playing a crucial role in keeping contacts alive with North Korea after Trump abruptly canceled the summit late last month. South Korea has led parallel talks with Kim’s regime over initiatives that include plans to open a quasi-diplomatic “liaison office” in the North.
But his government was surprised by Trump's announcement following the summit that the U.S. will be suspending military exercises with South Korea, without specifying which of these drills and when this might happen. His government was not informed of the decision prior to the announcement, and the two leaders spoke over the phone only after the summit when Trump was aboard Air Force One leaving Singapore.
In Japan, which had hoped that North Korea would commit to re-opening the issue of abducted Japanese citizens, there was relief that Trump said he had at least raised the issue with Kim.
China issued a hedged statement about the possibility of relaxing sanctions on North Korea -- but saw its preferred approach to U.S.-North Korean relations spelled out virtually intact in the Trump-Kim statement.
Beijing got everything it wanted, wrote Abraham Denmark, director of Asia program at the Woodrow Wilson International Center for Scholars, in an email. By halting military exercises with South Korea, Trump "removed a major irritant for Beijing," he wrote.
"I expect Beijing sees itself as a big winner coming out of today's summit," he continued. "But I also suspect that some in China are nervous about the United States and North Korea getting too close. I expect Beijing to accelerate its engagement of North Korea, with high-level political meetings and even economic assistance and infrastructure development. China will make sure that it retains significant leverage and cannot be bypassed or ignored.”
A spokesman for China’s Foreign Ministry said it would consider easing sanctions but only if Pyongyang met conditions laid out in U.N. resolutions.
“China has consistently held that sanctions are not the goal in themselves. The Security Council’s actions should support and conform to the efforts of current diplomatic talks toward denuclearizing the Korean Peninsula and promote a political solution for the peninsula,” spokesman Geng Zhuang said.
China’s enforcement of sanctions is a linchpin to keeping economic pressures on North Korea, which has depended on Beijing as a lifeline for trade and assistance for decades.
Lu Chao, a Korea expert at the Liaoning Academy of Social Sciences in Shenyang, said the statement in Singapore reflected China’s demands and goals.
“It’s historic progress, and we can believe that the peninsula has begun to start toward peace,” he said.
But North Korea's other neighbor in the Pacific, Japan, was left without what it wanted most from the summit -- a clear declaration that North Korea would reopen talks over the abductions of Japanese citizens decades ago.
Japanese leaders appeared satisfied, nonetheless, with what they got: Trump’s public promise that he raised the issue with Kim and that the North was “working on that.”
Even the vague comment by Trump saved Japan’s prime minister, Shinzo Abe, a major political embarrassment after he personally lobbied Trump to champion the issue. “I highly value the fact President Trump mentioned things that I had told him the other day,” Abe told reporters. “I’d like to thank President Trump that he raised the abduction issue clearly.”
For Japan, the abductions remain a major obstacle to joining the United States and South Korea in the growing engagement with the North.
Leaving the abduction issue off the Trump-Kim statement — as well as any direct mention of human rights abuses by the North — could add political pressures from opponents of Abe, who has built an image as one of the world leaders closest to Trump. Afterward, Trump said he discussed rights issues with Kim but gave no details.
Yoshimasa Suenobu, a professor at Tokai University and a commentator on TV Asahi, said he did not believe Abe expected the abduction issue to be part of any declaration.
“I think it’s good enough that President Trump kept his word and mentioned it. Things weren’t going anywhere, but thanks to two odd men [Trump and Kim], now they’ve started moving again,” Suenobu added. “So the outcome wasn’t the greatest, but Trump did the least he could do.”
North Korea has admitted to kidnapping 13 people from Japan in the 1970s and 1980s to train as spies. Pyongyang allowed five of the abductees to return to Japan with their families in 2002, but it insists that the eight others died. Japan suspects hundreds more may have been taken captive.
Trump told reporters that he “absolutely” raised the issue. But he gave no indications of Kim’s response or what actions the North might take.
“They are going to be working on that. We didn’t put it down in the document, but it’s going to be worked on,” Trump said in the news conference after the summit.
North Korea has claimed the abduction issue has been “resolved” and accused Japan of trying to disrupt its attempts at outreach to South Korea and the United States. In response, Abe has said Japan will not normalize relations with Pyongyang or offer aid unless a full accounting of the abductions is conducted.
As recently as last week, Abe held meetings with Trump in Washington to ask that the abduction issue be added to the Singapore summit agenda. On Saturday in Canada, Abe called for direct talks with North Korea “to resolve the abduction issue.”
Sakie Yokota, mother of abductee Megumi Yokota, told broadcaster NHK that she felt a “miraculous thing happened” in Singapore to possibly revive the abduction issue with North Korea.
Shigeo Iizuka, the head of a group representing abductees’ families and whose sister Yaeko was abducted, also told NHK that “the Japanese abduction issue is getting attention again,” adding: “We welcome it and have high hopes.”
Former abductee Kaoru Hasuike told Fuji News Network he was a little disappointed that the issue wasn’t in the joint declaration. “But he said he had mentioned it, so I think we will learn more about it soon,” he said. “Since the agreement is signed, Japan should accept it and take this momentum to realize a summit between Japan and North Korea.”
Other historical disputes loom over North Korea’s eventual normalization in the region, including issues between nominal allies.
South Korean activists have held round-the-clock vigils outside the Japanese Embassy in Seoul seeking to keep alive the memory of Korean women used as sex slaves by Japanese forces during World War II. Abe’s government also is angered by South Korea’s decision to reopen discussions over a 2015 deal that was intended as a “final and irreversible” conclusion to sex slave reparations and other claims.
Mahtani contributed from Washington. Emily Rauhala in Beijing and Yuki Oda in Tokyo contributed.