By affirming that American troops can stay in South Korea under a possible nuclear deal, did North Korean leader Kim Jong Un just remove a key stumbling block in negotiations with the United States?

South Korean President Moon Jae-in said Thursday that Kim isn’t asking for the withdrawal of U.S. troops from the Korean Peninsula as a precondition for abandoning his nuclear weapons. If true, this would appear to remove a major roadblock to a potential deal under which Kim relinquishes his nuclear arsenal.

The North has for decades tied its development of nuclear weapons to what it has labeled a “hostile” U.S. policy — a reference to the 28,500 troops on its “doorstep” in South Korea, as well as the roughly 50,000 troops stationed in Japan. Perhaps more immediately pressing for Pyongyang, it has also linked this policy to the U.S. pulling back the “nuclear umbrella” Washington has extended over its closest Asian allies. Pulling that back would end the U.S. commitment to “extended deterrence” — its threat of nuclear retaliation if either country is attacked by the North.

“The North Koreans did not present any conditions that the United States could not accept, such as the withdrawal of American troops in South Korea,” Moon was quoted as telling media executives Thursday.

“They only talk about an end to hostilities against their country and about getting security guarantees,” he added.

When special envoys dispatched by Moon met with Kim in Pyongyang last month, the North Korean leader said his country would no longer need nuclear weapons if it did not feel “threatened militarily” and was provided with “security guarantees.”

But despite Moon’s comments, experts noted an important caveat — that the North was not explicit in saying it had given up on its longtime demand that U.S. troops leave the South. In reality, any clear picture of what Kim will actually ask in return for denuclearizing will likely not come into focus until his summit with Moon next Friday or even his planned meeting with U.S. President Donald Trump, which the president said could come by June.

“North Korea has an enduring interest in weakening U.S. alliances in the region and the military forces that deter and contain them,” said Adam Mount, a senior fellow at the Federation of American Scientists. “It is still possible that Kim reverses course when he sits down with Trump, but perhaps Kim is willing to set aside military interests in order to avoid war.”

The move by the North could also be part of what Nick Bisley, an Asia expert and head of the School of Humanities and Social Sciences at La Trobe University in Australia, called a “pre-negotiation negotiation” gambit “in what has been a wildly unpredictable period.”

He said there are several ways to interpret the North’s moves.

“They may want to signal their security confidence in the face of what they perceive to be a belligerent U.S.,” and that they are comfortable with that in the long run, Bisley said.

Another view is that “they feel secure with nukes and the USFK (U.S. Forces Korea) is not a threat in the longer run because of the nukes, i.e. they don’t mean denuclearization in the way the U.S. and others mean.”

His other explanation: The move is “disingenuous.”

In his remarks Thursday, Moon also said that North Korea has expressed a commitment to the “complete denuclearization of the Korean Peninsula,” though Washington remains wary of this claim and has vowed to continue heaping “maximum pressure” on Pyongyang.

The U.S. acknowledged earlier this month that the North said it is ready to discuss the denuclearization issue, but experts and observers say such a move is extremely unlikely in the near-term and highlights a potentially dangerous perception gap between the two countries.

Moon, however, has tried to tamp down these fears.

“I don’t think denuclearization has different meanings for South and North Korea. The North is expressing a will for a complete denuclearization,” he said Thursday.

The South Korean leader also said agreements on denuclearization, establishing a peace regime and the normalization of diplomatic ties between the two Koreas and the U.S. “will not be difficult” to reach at the inter-Korean summit and Kim-Trump meeting.

Moon, a liberal who has long supported engagement with the North despite his hard-line take after numerous North Korean weapons tests last year, is eager to hold a successful summit and also lay the groundwork for Kim and Trump to reach some kind of a deal on the North’s nuclear ambitions.

This week, the odds of the Trump-Kim summit even happening at all rose significantly when the U.S. leader confirmed CIA chief Mike Pompeo had secretly visited the isolated North for face-to-face talks with Kim earlier this month as part of planning for what would be the first-ever meeting of a sitting American president and North Korean leader.

Trump later voiced hopes of a successful summit but warned that he could “respectfully” walk away if it appears the talks will not be “fruitful.”

But for now, North Korea is “saying all the right things to make sure a summit happens,” Mount said.

He said Kim’s dangling of the apparent concessions could ultimately be a potential pitfall for the U.S. side.

“Trump has not taken a cautious approach to these negotiations. He will likely take this shift in tone as an encouraging sign,” Mount said of the apparent dropped U.S. troop withdrawal demand and other modifications the North has made to its stance.

“Even without U.S. concessions on defense posture, Pyongyang could still come out well ahead by stalling for time, easing China’s sanctions enforcement, causing frictions between the allies, and reaping the legitimacy of a presidential summit.”

Still, there may be another type of logic behind Kim’s diplomatic opening.

After cementing his domestic position through sometimes bloody purges and bolstering his international standing via a nuclear weapons program that he declared “complete” in November, Kim may be pivoting toward dialogue and diplomacy.

This could mean he now has “the confidence to accept credible security guarantees that come with building a ‘permanent peace regime,’ assuming Trump offers them,” John Delury, an associate professor of international relations at Yonsei University in Seoul, wrote Wednesday on the Monkey Page Blog hosted by The Washington Post. “In return, Kim looks strong enough to make real concessions in halting, dismantling and eliminating his strategic weapons program in return.”

Sanctions, however, wrote Delury, “keep Kim from achieving his ultimate ambition — what he wants at least as ardently as a nuclear deterrent — making North Korea a wealthy country.”

Delury said Kim had telegraphed these ambitions in 2013 with the unveiling of his byungjin (dual progress) policy that focuses on the simultaneous development of its economy and nuclear weapons program.

Kim’s diplomatic outreach, he wrote, “should be understood as part of the unfolding of byungjin, and probably signals a pivot from security to prosperity, isolation to integration, ICBMs to SEZs (special economic zones).”

The young North Korean leader, he wrote, “appears ready to make that transition, and, understood in that light, the summit presents a rare opportunity for progress.”