WASHINGTON — Attorney General William Barr did not submit a summary of special counsel Robert Mueller's report to Congress Saturday but he could still do so on Sunday.

Barr had said in a letter to the House and Senate Intelligence Committee on Friday that he hoped to make Mueller's "principal conclusions" available to them some time over the weekend.

"I am reviewing the report and anticipate that I may be in a position to advise you of the Special Counsel’s principal conclusions as soon as this weekend," Barr said in the letter.

A senior Justice Department official said that Barr, who was in his office at the department reviewing Mueller's report, would not be informing Congress of the findings on Saturday.

Meanwhile, President Donald Trump was at his Mar-a-Lago resort in Florida, where he planned to remain for the rest of the weekend. White House deputy press secretary Hogan Gidley told reporters that the president, who played golf on Saturday, is described as being "in good spirits."

There was no plan as of Saturday afternoon for the president to any make public comments on the Mueller report, which the White House said it has not seen.

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Members of Congress were scheduled to return to Washington on Monday following a week-long recess. All eyes will be on Capitol Hill where key oversight committees plan to scrutinize Mueller's findings.

Speaker Nancy Pelosi, D-Calif., told House Democrats during a Saturday conference call that she would reject any classified briefing offered to top congressional leaders, reiterating that any briefing must be unclassified. More than 120 House Democrats participated in the more than 35-minute call, which also featured Democratic caucus chairman Hakeem Jeffries, D-N.Y., and relevant committee chairmen.

"The takeaway from this call is that the American deserve the truth, to know the truth, transparency is the order of the day — that is what Chuck [Schumer] and I said in our statement," Pelosi said during the call, according to a congressional source on the call.

In a letter to members of the Democratic caucus, Pelosi said Saturday they would insist that any briefings provided to committees should be done in an unclassified manner so that lawmakers can speak freely "about every aspect of the report." She added that the underlying findings of Mueller's investigation "must be provided to Congress and the American people."

"The Attorney General’s offer to provide the Committees with a summary of the report's conclusions is insufficient," wrote Pelosi. "Congress requires the full report and the underlying documents so that the Committees can proceed with their independent work, including oversight and legislating to address any issues the Mueller report may raise."

The House recently voted unanimously that the full Mueller report be released to the public.

House Republicans held their own conference call Friday night to discuss the Mueller report being completed, NBC News learned from two sources who were on the call. All GOP leaders and ranking members from committees were among those on the call. Sources said that there was optimism from members about the news regarding no additional indictments, but they were also proceeding with caution and a "let's wait and see" mentality.

During a conference call with reporters Saturday, Sen. Chris Coons, D-Del., referred to reports that said Senate Judiciary Committee Chairman Lindsey Graham, R-S.C., gave a defense of Trump Friday night at Mar-a-Lago and the crowd erupted into chants of "lock her up."

"I think all of this points to ways in which President Trump has undermined some of our core values, and it would be disheartening if the chairman of the Senate Judiciary Committee were sort of piling on in that effort," Coons said.