The historic Singapore summit between United States President Donald Trump and North Korea’s leader Kim Jong-un is back on after a frantic round of diplomacy.

Just a week after pulling out of the scheduled talks on June 12, Trump announced that they would take place following a meeting with North Korean envoy General Kim Yong-chol at the White House.

During the talks, the general hand-delivered a letter from the North Korean leader. According to the US media, Trump initially told reporters the letter was “very interesting” before later admitting that he had not read it yet.

“We’re meeting with the chairman on June 12 and I think it’s probably going to be a very successful – ultimately a successful process,” Trump said on the South Lawn after his meeting with Kim Yong-chol for more than an hour in the Oval Office.

This latest development came after US and North Korea both deployed the widest range of diplomatic assets.

With North Korea customarily preferring its diplomatic engagement to take place well behind closed doors, little information had leaked out before Trump’s announcement. However, three channels came into play.

Senior officials met in New York in the US, while mid-level officials were in Panmunjom, the truce village in the Demilitarized Zone between the two Koreas. Working-level officials also met in Singapore, the venue for the big event.

The overtime work by officials from the two nations, which have been at daggers drawn since the Korean War broke out in 1950, and whose leaders have never met, indicated that both parties were seriously searching for common ground to form the basis of the summit.

Meanwhile, Russian Foreign Minister Sergei Lavrov also met with Kim Jong-un in Pyongyang, the North Korean capital.

Action on all fronts

In New York, Vice-Chairman of the [North] Korean Workers Party Central Committee Kim Yong-chol met US Secretary of State Mike Pompeo on Wednesday, US-time. Kim Yong-chol is the highest level North Korean official to visit the US since 2000.

Images released showed Pompeo, Kim Yong-chol and two aides talking, apparently amicably, over a meal at Millennium Hilton New York One UN Plaza. Earlier video footage showed Kim Yong-chol arriving at the venue, with a plain-suited security presence, both US and North Korean, much in evidence.

Kim Yong-chol and Pompeo are believed to have held extensive talks on Thursday, paving the way for the meeting with Trump. Pompeo, a former CIA director, led Trump’s diplomatic outreach to Pyongyang and has met North Korean leader Kim Jong-un on at least two occasions.

It is not clear why Kim Yong-chol traveled to New York rather than Washington, but North Korea lacks diplomatic relations with the US, so it has no embassy in Washington. It does, however, maintain a UN mission in the city. That offers him a chance to confer with his country’s senior overseas diplomats, as well as a secure location during his American stay. And reciprocity may be at play: Pompeo has twice traveled to Pyongyang, hence Kim’s flight to the US.

Kim Yong-chol, a four-star general and former head of North Korea’s formidable espionage and special operations arm, the Reconnaissance General Bureau, has served all three of North Korea’s Kims. He, along with Kim Jong-un’s younger sister Kim Yo-jong, are widely seen as the two key advisers to the head of state. Kim Yong-chol, who many in South Korea hold responsible for a torpedo attack on the South Korean corvette Cheonan, which killed 46 sailors in 2010, is the harder-edged of the two. He is also a highly experienced negotiator.

Meanwhile, in Seoul, ex-US Ambassador to South Korea, Sung Kim, a Korean-American who speaks fluent Korean and is an expert on peninsula affairs, led a US delegation which included White House and Defense officials. Sung Kim’s group met a North Korean delegation, headed by Vice-Foreign Minister Choe Son-hui for three hours on Sunday in Panmunjom. They met again on Wednesday, but did not, apparently, meet on Monday or Tuesday. Informed sources say the lack of meetings on Monday and Tuesday were due to the North Korean side having to report, digest and discuss what the Americans had said on Sunday.

Sung Kim is currently the US ambassador to Manila. The fact that he has been indefinitely detached from that duty indicates the seriousness of US intentions: a diplomatic source said it was “very unusual” for such a thing to happen.

The third “channel” at work was in Singapore. Working-level parties from both North Korea and the United States are in the island state, looking into venues and logistics.

Moscow makes a play

With Beijing, the two Korean capitals and Washington all engaged in high-level diplomatic maneuvering in recent weeks, Moscow has appeared sidelined. However, Foreign Minister Sergey Lavrov has suggested, in a message from Pyongyang following a meeting with Kim Jong-un, that the time has come for international sanctions to be eased.

That contradicts the US policy of maximum pressure. There is no way that UN Security Council sanctions on North Korea will be lifted unless Washington agrees, as it holds a veto. However, Beijing and Moscow have the option of simply relaxing implementation of the sanctions, and weakening Washington’s hand.

Experts are divided over how hard North Korea has been hit. Some believe sanctions are biting and that explains why North Korean vessels have resorted to refueling from Chinese and Russian ships on the high seas; analysts at Seoul’s Sejong Institute believe Pyongyang’s foreign exchange reserves will expire by the end of the year. But recent visitors to the North have told Asia Times there are significant indications of prosperity in Pyongyang, including a hive of prestige construction projects.

Lavrov also suggested that Kim Jong-un meet Russian President Vladimir Putin, who, following recent meetings with French President Emmanuel Macron and Japanese Prime Minister Shinzo Abe, appears keen to flex his diplomatic muscles.

Top-down talks and cautious optimism

The last-minute flurry of activity follows rollercoaster developments last week, when Trump announced that he was canceling the summit, citing hostile messages from North Korean state media. The following day, North Korea issued a conciliatory statement, which was welcomed by Trump, and requested an emergency summit with South Korean President Moon Jae-in.

“I think there is a lot of catch up, as in the past these things were usually bottom-up – the groundwork is done ahead of time – but this is all sudden, due to Trump’s impulsive nature,” said Dan Pinkston, a Seoul-based international relations expert at Troy University.

Still, a top-down process appears to be working with hierarchical North Korea. “It seems consistent with how their system is organized, [officials] are on a very tight leash, they have to receive guidance from their superiors,” Pinkston added. “Once guidance goes through the channels to the working level, they are empowered.”

While most experts are cynical about the possibility of a substantive deal being struck between Pyongyang, which few expect to denuclearize, and Washington – which wants complete, verifiable, irreversible disarmament, or CVID – some express a guarded optimism, as the current process is unprecedented in North Korean-American relations.

“I hope for the best, as this is a rare opportunity for solving the North Korean nuclear problem,” said Park Jin, a former National Assemblyman who currently heads the Korean-American Association in Seoul. “This could provide a decisive turning point. That is the hope.”