North Korea and the United States may have come to an understanding over what to do about Pyongyang’s nuclear weapons. If so, it would be a dramatic development in the ongoing negotiations over the country’s nuclear program.

Secretary of State Mike Pompeo said on Friday that his recent talks with North Korean leader Kim Jong Un this week were “warm” and “substantive” and that they are in “complete agreement about what the ultimate objectives are” for the upcoming summit between Kim and President Trump in Singapore on June 12.

“We have a shared vision for what we hope, when this process is completed, the Korean Peninsula looks like,” Pompeo said, speaking at a joint press conference with South Korean Foreign Minister Kang Kyung-wha in Washington.

But, he added, any agreement with Pyongyang must have a “robust verification program” to ensure that North Korea is serious about dismantling its nuclear weapons program.

That the two sides are in “complete agreement” about the desired outcome of the talks is hugely significant if true.

Although Pyongyang has expressed its willingness to “denuclearize” — something President Trump tweeted enthusiastically about back in late April — experts have been warning that Washington and Pyongyang may actually be talking about two very different things when they use that word.

North Korea has consistently stated that it would be willing to give up its nuclear weapons — but only if the US withdraws the 28,500 American troops stationed in South Korea. That’s not the vision of denuclearization that the US and South Korea have. They just want North Korea to dismantle its entire nuclear program. Period.

If the two sides have truly come to an understanding of what the other side is asking for and offering in return, that’s a major step forward.

Here’s what a US-North Korea deal might look like

Pompeo also seemed to suggest that they had begun to move to the next phase of negotiations, saying that during his talks he and Kim “began to work through the modalities, how we would achieve that” shared vision.

Those comments seem to echo recent reports from South Korean media that the US and North Korea have made some progress on outlining what a potential nuclear deal might look like.

A person familiar with the White House’s current thinking on the North Korea negotiations explained what the US is envisioning as a possible deal.

“North Korea agrees in a certain time table to give up nukes and inspectors go in,” the person, who requested anonymity to discuss sensitive negotiations, told me. “Inspectors quantify and log North Korea’s capabilities. They get a reward for it and maybe some sanctions come off. Then, North Korea gets rid of some nukes. Pyongyang gets a reward. Then, North Korea takes down their nuclear reactors. They get another reward. And on and on.”

A State Department spokesperson would neither confirm nor deny that characterization of a potential deal, but said that “North Korea has confirmed to us its willingness to talk about denuclearization” and that “the global maximum pressure campaign will continue until North Korea denuclearizes” — referring to the US-led effort to economically and diplomatically isolate North Korea in order to convince Kim to come to the negotiating table.

(A spokesperson for the National Security Council said only, “Your source knows nothing.”)

But that broad outline of a deal tracks with previous statements from Trump administration officials that the US would not make any “substantial concessions, such as lifting sanctions, until North Korea has substantially dismantled its nuclear programs.”

South Korean Foreign Minister Kang Kyung-wha reiterated that sentiment at Friday’s press conference. “We very much hope to see further steps, more concrete steps toward denuclearization at the US-North Korea summit, so we’re not talking about sanctions relief at this point,” she said.

There’s still a month to go before Trump and Kim are scheduled to sit down together, and a both the US and North Korea could certainly change their minds at any point between now and then.

A US-North Korea deal could still fall apart

What’s more, even if Trump and Kim do walk away from the summit with a handshake or even signed agreement, it’s possible North Korea could walk out on the deal.

North Korea has also historically been a very tough country to negotiate with, in large part because it routinely breaks the deals it agrees to. The US and other countries have been trying to come to a diplomatic, negotiated agreement with North Korea over its nuclear program since 1985. It’s broken its commitments multiple times with the US, including walking out on a denuclearization deal in 2009.

Still, it’s remarkable that both sides may have agreed simply on what they will discuss. Now we have to wait a month to see if they’ll actually complete a deal.