President Trump stops to talk to reporters and members of the media as he walks from the Oval Office to board Marine One on Wednesday. (Jabin Botsford/The Washington Post)

President Trump on Saturday falsely accused the New York Times of using an unnamed source “who doesn’t exist” in a story on negotiations between the United States and North Korea, but the official cited spoke to reporters Thursday in a briefing arranged by the White House.

“The Failing @nytimes quotes ‘a senior White House official,’ who doesn’t exist, as saying ‘even if the meeting were reinstated, holding it on June 12 would be impossible, given the lack of time and the amount of planning needed,’” Trump tweeted Saturday morning. “WRONG AGAIN! Use real people, not phony sources.”

The senior White House official cited by the Times spoke to dozens of reporters Thursday at the White House and on a conference call to brief them on Trump’s decision earlier that day to cancel his June 12 summit in Singapore with North Korean leader Kim Jong Un.

The Washington Post, which participated in the briefing, agreed to the rules as laid out by White House press officials at the time, which were to refer to the briefer as a senior White House official. The Post also used information from that briefing in subsequent stories and continues to abide by the agreed upon ground rules.

When an Associated Press reporter asked Thursday why the briefing was not on the record, the official noted that Trump had already spoken on the topic through his letter to Kim, as well as at a bill-signing event earlier that day. The White House wanted to “let the president’s remarks stand,” the official said. 

The White House press office did not respond to a request for comment Saturday on why Trump was accusing the Times of falsifying the source when it arranged the briefing for reporters and insisted that the official not be named.

Administrations routinely brief reporters, on background, on a variety of issues, but it is extraordinary for a president to then accuse reporters of making up the officials who take part in the event.

The Thursday briefing was convened hours after Trump’s surprise announcement that he was canceling the highly anticipated summit with Kim because of what he called open hostility and nuclear threats coming from Pyongyang.

The senior official cast doubt on whether the landmark meeting could end up happening as scheduled on June 12 even if the United States and North Korea reversed course and decided to meet because time was running short.

“There’s been an enormous amount of preparation that’s gone on over the past few months at the White House, at State and with other agencies and so forth, but there’s a certain amount of actual dialogue that needs to take place at the working level with your counterparts to ensure that the agenda is clear in the minds of those two leaders when they sit down to actually meet and talk and negotiate and hopefully make a deal,” the official said. “June 12 is in 10 minutes.”

On Friday, one day after canceling the summit, Trump struck a much more positive tone and told reporters it was still possible that his meeting with Kim could happen June 12.

In his Saturday tweet, Trump seemed to take issue with how the official’s remarks were characterized. The Times wrote that holding the summit on June 12 would be “impossible” given the short time frame, citing the official while not directly quoting. The official did not use the word impossible.

“As with so many issues involving this president, the views of his aides often have little effect on what he actually says,” the Times’s story reads. “On Thursday, for example, a senior White House official told reporters that even if the meeting were reinstated, holding it on June 12 would be impossible, given the lack of time and the amount of planning needed.”

The Times did not respond to a request for comment about whether it stood by its characterization of the official’s comments.

“Best way to alleviate the President's concern about anonymous sources would be for WH to name the official,” David Sanger, one of the two Times reporters who wrote the story referenced by Trump, said on Twitter on Saturday.