The Trump administration continued on Wednesday to soften its rhetoric on North Korea, with a senior official spelling out terms for talks over its nuclear arms program. Not long ago, the administration declared negotiations would be a waste of time.

Any negotiations with Pyongyang and other countries over its nuclear and long-range missile development would have to meet the standard of being “authentic talks,” the senior administration official told reporters on Air Force One heading to Beijing. For negotiations to begin, the North would first have to “reduce the threat, [end] provocations, and [move] toward sincere steps to ultimately denuclearize,” the official added.

In another dramatic change, the senior official even discussed things the Trump administration would insist be a part of any potential eventual pact with North Korea.

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For instance, Trump would demand legitimate means of verifying that the Kim government was living up to its commitments to be included.

“It has to be verifiable cases,” the official said, also signaling the administration favors negotiations involving the North and other countries than just the United States. The White House has been firm that so-called “bilateral” talks are off the table — at least for now. To that end, the senior official dinged past administrations’ “very disappointing history” of trying to talk directly to Pyongyang, dating back to the George H.W. Bush administration.

One thing that could wreck even the potential for negotiations: Kim Jong-un’s government refusing to discuss its nuclear arms.

“That is a non-starter for us,” the senior official said.

The administration’s sudden willingness to even publicly discuss negotiations and the terms of an agreement is a departure from its own recent rhetoric.

On Oct. 7, Trump himself tweeted that “only one thing will work” when it comes to the North.

“Presidents and their administrations have been talking to North Korea for 25 years, agreements made and massive amounts of money paid … hasn’t worked, agreements violated before the ink was dry, makings fools of U.S. negotiators,” Trump wrote that day, hinting at military action being the sole effective option. “Sorry, but only one thing will work!”

Presidents and their administrations have been talking to North Korea for 25 years, agreements made and massive amounts of money paid……

— Donald J. Trump (@realDonaldTrump) October 7, 2017

And on Oct. 2, White House Press Secretary Sarah Huckabee Sanders dismissed the notion of talks.

“We’ve been clear that now is not the time to talk,” Sanders said. “The only conversations that have taken place were that … would be on bringing back Americans who have been detained. … Beyond that, there will be no conversations with North Korea at this time.”

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The senior official’s striking new tone came a day after Trump, speaking on Korean soil in Seoul, warned North Korea that he would defend the United States and its allies with America’s full arsenal of military weapons if it attacks but also urged the Kim government to open negotiations with the U.S. and other countries.

Hours before his aides’ briefed reporters on the executive jet, Trump delivered a speech to the South Korean legislature in which he struck both peace-seeking and hawkish tones toward North Korea.

“America does not seek conflict or confrontation, but we will never run from it,” Trump said, delivering this stern warning to Kim: “Do not try us.”

“History is filled with discarded regimes that have foolishly tested America’s resolve,” he said to sometimes-tepid applause in the large hall. “Anyone who doubts the strength or determination of the United States should look to our past and you will doubt it no longer. We will not permit America or our allies to be blackmailed or attacked.”

On a lighter note, Trump may find himself unable to use his preferred method of communicating with his supporters while in China: Twitter.

“I’m sure we’ve got the gear aboard this airplane to make it happen,” the senior official said of most American social media sites, including Twitter, being banned there. “But it is noteworthy that none of the major Western platforms for social media are even allowed to operate in China.”