By Christine Kim and David Brunnstrom
SEOUL (Reuters) - Tough sanctions will remain on North Korea until its complete denuclearization, the U.S. secretary of state said on Thursday, apparently contradicting the North's view that the process agreed at this week's summit would be phased and reciprocal.
U.S. President Donald Trump and North Korean leader Kim Jong Un issued a joint statement after their Singapore meeting that reaffirmed the North's commitment to "work toward complete denuclearization of the Korean peninsula", while Trump "committed to provide security guarantees".
Trump later told a news conference he would end joint U.S.-South Korean military exercises.
"President Trump has been incredibly clear about the sequencing of denuclearization and relief from the sanctions," Secretary of State Mike Pompeo told reporters after meeting South Korea's president and Japan's foreign minister in Seoul.
"We are going to get complete denuclearization; only then will there be relief from the sanctions," he said.
North Korean state media reported on Wednesday Kim and Trump had recognized the principle of "step-by-step and simultaneous action" to achieve peace and denuclearization on the Korean peninsula.
The summit statement provided no details on when North Korea would give up its nuclear weapons program or how the dismantling might be verified.
Skeptics of how much the meeting achieved pointed to the North Korean leadership's long-held view that nuclear weapons are a bulwark against what it fears are U.S. plans to overthrow it and unite the Korean peninsula.
However, South Korean President Moon Jae-In said the world, through the summit, had escaped the threat of war, echoing Trump's upbeat assessment of his meeting with Kim.
"What's most important was that the people of the world, including those in the United States, Japan and Koreans, have all been able to escape the threat of war, nuclear weapons and missiles," Moon told Pompeo.
Pompeo insisted North Korea was committed to giving up its nuclear arsenal but said it would "be a process, not an easy one".
Kim understood getting rid of his nuclear arsenal needed to be done quickly and there would only be relief from stringent U.N. sanctions on North Korea after its "complete denuclearization", Pompeo said.
Moon later said South Korea would be flexible when it comes to military pressure on North Korea if it is sincere about denuclearization.
Also on Thursday, North and South Korea held their first military talks in more than a decade. The talks followed on from an inter-Korean summit in April at which Moon and Kim agreed to defuse tension and cease "hostile acts".
Speaking later in the day in Beijing, Pompeo thanked China for its efforts to ensure the Trump-Kim summit happened, but also struck a note of caution.
"I wanted to thank you for the kind words you had for President Trump and work he did to put us in this place where we now believe we have a path forward which can truly, for the first time in so many years, create peace on the peninsula," Pompeo told the Chinese government's top diplomat, State Councillor Wang Yi.
"And there is still a lot of work to do. There are still risks that we won't achieve that."
Wang said the meeting brought the Korean peninsula nuclear issue back to the correct track of resolving it peacefully.
"It accords with the all parties' joint interests, including those of the United States and North Korea," he said.
'EVERYBODY MUCH SAFER'
The United States has long insisted on complete, verifiable and irreversible denuclearization by North Korea.
But the summit statement reference to North Korea committing to work toward the complete denuclearization of the peninsula has used been by North Korea in the past to include a U.S. nuclear umbrella in the region, and echoes promises it has failed to keep.
Trump returned to the United States on Wednesday and took to Twitter to hail the meeting, the first between a sitting U.S. president and a North Korean leader, as a major win for American security.
"Everybody can now feel much safer than the day I took office," Trump tweeted. "There is no longer a nuclear threat from North Korea."
Democratic critics in the United States said the agreement was short on detail and the Republican president had made too many concessions to Kim, whose country is under U.N. sanctions for its nuclear and weapons programs and is widely condemned for human rights abuses.
Pompeo said Trump's comments about the reduced threat from North Korea were made "with eyes wide open".
"It could be the case that our effort won’t ... work but we are determined to set the conditions so that we can right this failure of decades and reset the conditions for North Korea's participation in the community of nations," Pompeo said after a trilateral meeting with South Korean Foreign Minister Kang Kyung-wha and Japanese Foreign Minister Taro Kono.
Japan has reacted to Trump's plan to cancel military exercises with South Korea with concern, saying the drills are vital for East Asian security.
Two North Korean missiles flew over Japan last year as North Korea made rapid advances in developing a missile capable of striking the U.S. mainland with a nuclear warhead.
Tokyo is working on arranging a meeting between Prime Minister Shinzo Abe and Kim, with one possibility being an Abe visit to Pyongyang around August, the Yomiuri newspaper reported.
A Japanese government source familiar with the matter told Reuters officials aimed to discuss a summit with North Korean officials at a regional security conference in Mongolia on Thursday and Friday.
Kang said South Korea and the United States shared the same goals and approach to achieving denuclearization.
"The issue of South Korea-U.S. joint exercises is one that should be discussed," Kang said. "But the issues of the alliance should be dealt with under the premise we maintain a joint ironclad defense posture."
The U.S. intelligence assessment of the nuclear and other military threat posed by North Korea to U.S. and allied forces remained unchanged despite Trump's and Moon's assertions about the North Korean nuclear threat being over, a senior U.S. official responsible for studying the North Korean military said.
U.S. officials said it was unclear what types of training involving U.S. and South Korean troops might cross into Trump's now forbidden zone of "war games". But big, joint U.S.-South Korean exercises appeared off-limits under the new guidance.
"Make no mistake, we are going to maintain the readiness of our forces in South Korea," said one U.S. official, speaking on condition of anonymity. The official acknowledged, however, it was still not certain how that was going to happen.
The United States maintains about 28,500 soldiers in South Korea, which remains in a technical state of war with the North after the 1950-53 Korean War ended in a truce rather than a peace treaty.
(Reporting by David Brunnstrom and Christine Kim in SEOUL; Additional by Josh Smith and Hyonhee Shin in SEOUL, Yoshifumi Takemoto and Chang-Ran Kim in TOKYO, Michael Martina in BEIJING and Phil Stewart in WASHINGTON; Writing by Lincoln Feast; Editing by Paul Tait, Robert Birsel)