North Korean Foreign Minister Ri Yong-ho gave a press conference from Hanoi, Vietnam, on Thursday in which he disputed U.S. President Donald Trump’s account of unsuccessful negotiations with dictator Kim Jong-un.

Ri claimed North Korea offered substantial concessions and asked for only partial relief from sanctions, whereas Trump said the North Koreans wanted all sanctions lifted in exchange for only nominal progress on denuclearization.

“Basically, they wanted the sanctions lifted in their entirety and we couldn’t do that,” Trump said on Thursday.

“He wants to de-nuke, but he wants to do some areas that aren’t what we want,” Trump said of Kim.

Ri contradicted Trump’s remarks in an unusual press conference, claiming Kim offered a “realistic proposal” to “permanently and completely dismantle all nuclear material production facilities” at its main production site, Yongbyon, “in the presence of U.S. experts.”

In exchange, Ri said Kim asked only for the United States to lift “sanctions that impede the civilian economy and the livelihood of our people.”

Trump specifically referenced Yongbyon in his comments, saying it did not represent the totality of North Korea’s capacity for creating weapons-grade nuclear material. Some media outlets incorrectly reported that Ri claimed Pyongyang was willing to dismantle all of its plutonium and uranium production facilities, but he mentioned only Yongbyon.

Ri said Trump demanded “one more measure” beyond dismantling Yongbyon, a concession North Korea was evidently unwilling to grant, but he did not explain what it was. He said only that “it became crystal clear that the U.S. was not ready to accept our proposal.”

Australia’s News.com speculated Kim balked at providing a full inventory of North Korea’s nuclear weapons to the United States, fearing the weapons could be targeted and destroyed by American airstrikes.

U.S. Secretary of State Mike Pompeo suggested North Korea only needed to “do just a little bit better” to make a deal, but Ri ruled out further negotiations at his press conference, stating North Korea’s proposal “will never be changed.”

Trump’s version of the negotiation received support on Thursday from an unlikely source, House Speaker Nancy Pelosi (D-CA), who criticized Trump for holding the summit at all but said he was right to walk away from the table.

“What we want is denuclearization. They didn’t agree to it in the first meeting. They didn’t agree to it in the second meeting. They wanted lifting sanctions without denuclearization. I’m glad that the President walked away from that,” Pelosi said.