The White House responded with cautious optimism Tuesday to North Korea's reported proposal to hold "candid talks" with the United States and South Korea, and to put its nuclear weapons and missile testing programs on hold while engaged in dialogue.
"I think they are sincere," said President Donald Trump, who attributed the apparent change in attitude to the tough sanctions and other actions that the United States has applied and pushed others to impose on North Korea.
"Hopefully it's positive; hopefully it will lead to a very positive result," he said.
Word of North Korea's willingness to hold talks came from South Korean officials, returning from what they described as productive meetings in the North, during which Pyongyang said it was prepared to discuss denuclearization and normalizing relations.
North Korea did not confirm South Korea's version of events, saying simply that the two sides "made a satisfactory agreement" during the meeting between the North's leader, Kim Jong Un, and envoys sent by the South's president, Moon Jae-in.
"We don't know yet" the full parameters of the dialogue, said a senior administration official, who spoke to reporters on the condition of anonymity. Senior officials from Seoul are expected to travel here later this week to provide more details.
In the meantime, "I think it's a good idea for everybody to take some perspective, take a deep breath, [and] keep in mind we have a long history, 27 years, of talking to North Koreans," the official said. The official added that there is "also a 27-year history of them breaking every agreement they've ever made with the United States and the international community.
"We are open-minded, we look forward to hearing more. But the North Koreans have earned our skepticism."
Others were even more skeptical.
"Maybe this is a breakthrough. I seriously doubt it, but hope springs eternal," Director of National Intelligence Daniel Coats told the Senate Armed Services Committee.
Other intelligence officials shared his doubts. Lt. Gen. Robert Ashley, director of the Defense Intelligence Agency, noted to the committee that maintaining the threat of nuclear weapons is too vital to the regime's survival for Kim to give them up quickly.
"I'd caution against too much optimism because we've been down this road too many times before," said Abraham Denmark, a former Asia official at the Pentagon who is now director of the Asia Program at the Woodrow Wilson International Center for Scholars.
"Even if it's eventually successful, it's going to be difficult. There will be setbacks and uncertainty," Denmark said.
Lawmakers, while noting that North Korea should not be trusted, stressed that even imperfect talks were better than no talks.
Sen. James Inhofe, R-Okla., who has been chairing the Armed Services Committee hearings in the absence of Sen. John McCain, R-Ariz., counted himself "a little more optimistic" than Coats. "It is something that is kind of unprecedented in coming forth and saying under some conditions he would follow the denuclearization," he said.
Sen. Mazie Hirono, D-Hawaii, said that "any opening of a diplomatic channel toward easing the tensions and removing a clear threat from North Korea is a good thing." She noted that for such talks to succeed, the United States would need a much stronger diplomatic corps.
The Korean overtures come at a time when the United States has no ambassador in South Korea and no special representative on North Korea, and when the nominee for assistant secretary of state for East Asia has yet to be confirmed by the Senate.
But Trump himself seemed buoyant. Speaking at a news conference with Swedish Prime Minister Stefan Löfven, Trump was asked "to what do you owe" the reported North Korean offer. "Me," he replied, apparently referring to the sanctions, his harsh personal criticism of Kim, and the threat to rain down "fire and fury" on North Korea. "No," he quickly added as silence engulfed the room. "Nobody got that."
"I think they are sincere, but I think they are sincere also because of the sanctions and what we're doing in respect to North Korea," Trump said, describing the measures as "very strong and very biting." He also said that "the great help we've been given from China" has played a role, although there are repeated reports of both Chinese and Russian assistance in helping North Korea evade sanctions.
Sen. Lindsay Graham, R-S.C., agreed with Trump that his tough language and actions may have turned the tide in Pyongyang. If any denuclearization agreement is reached, Graham said in a statement, "the lion's share of credit will go to President Trump for his strong stand."
Earlier, when he met Löfven in the Oval Office, Trump directed blame for the failure of previous efforts to secure the nuclear disarmament of North Korea toward his three predecessors - former presidents Barack Obama, George W. Bush and Bill Clinton.
"This should've been handled over many years by many different administrations, but these are the cards we are dealt," Trump said.
Vice President Mike Pence appeared to be the White House's designated pessimist. "All options are on the table and our posture toward the regime will not change until we see credible, verifiable, and concrete steps toward denuclearization," he said in a statement.
The senior administration official said that U.S.-South Korean military exercises planned for this month, but postponed until after the Winter Olympics in South Korea, "will resume . . . naturally, allies are going to train their militaries together for defensive purposes."
North Korea has said a number of times in the past that it would give up its nuclear weapons under certain conditions, but has reneged on every deal it has ever signed. The scope of any proposed talks was not clear. At various times, Pyongyang has demanded the full withdrawal of the U.S. military from South Korea or the withdrawal of "nuclear" troops and weapons - of which there are none in the South. Pyongyang had also demanded the cancellation of U.S. military exercises in exchange for eliminating its own weapons.
Similarly, the Trump administration has not clarified whether North Korea must pledge the "denuclearization" Trump has demanded as a precondition for substantive talks or that it must be agreed upon at the end of negotiations.
But the sudden thaw could, at the very least, bring about a reprieve in the months of acute tensions on the Korean Peninsula.
During its visit to Pyongyang, a delegation led by Chung Eui-yong, the South Korean national security adviser, had a four-hour dinner with Kim and his wife, as well as other senior officials including Kim's sister, Kim Yo Jong, who went to South Korea for the opening of the Winter Olympics last month.
"The dinner proceeded in a warm atmosphere overflowing with compatriotic feelings," the North's official Korean Central News Agency said in a report, one of several that mentioned the Koreans' shared blood and implied that they were united together against the outside world.
During the Olympics, Pence met with the South's president, Moon. But a planned encounter with Kim's sister was scrapped by North Korea.
Chung said North Korea "made it clear" that it would not resume provocations - such as nuclear tests or intercontinental ballistic missile launches - while it was engaged in talks with the South. The regime, he said in Seoul, reiterated a willingness to talk with the United States, its avowed enemy since the Korean War, and "clearly affirmed its commitment to the denuclearization of the Korean Peninsula."
If events play out the way Seoul hopes, Moon will be meeting Kim for a summit on the southern side of the inter-Korean border late next month.
Moon's progressive predecessors both traveled to Pyongyang for summits with Kim's father, Kim Jong Il. Analysts had said it would be unseemly for a South Korean leader to make the same pilgrimage a third time.
The two sides agreed that the next summit will be held inside the Peace House at Panmunjom, the "truce village" straddling the Demilitarized Zone that divides the peninsula. The house is just over the southern side of the line. It would mark the first time since the Korean War ended in 1953 that the North Korean leader had crossed into the South and the first meeting between Kim and another head of state in his six years in power.
The two Koreas also agreed to establish a hotline between the leaders of the two sides to ease military tensions and to be able to consult closely. They will test the line with a phone call before the summit.
Fifield reported from Tokyo. Karoun Demirjian, Philip Rucker and Brian Murphy contributed to this report.