Senior Defense officials disputed reports that the Biden transition team was blocked from meeting with the Defense Department's intelligence agencies. Instead, the government officials say that mutually agreed-upon transition guidelines were not followed by the Biden intelligence transition team when they contacted the DOD intelligence agencies for meetings last weekend.

The transition guidelines specified that the requests for meetings with those agencies had to be made by Biden's Pentagon transition team. A senior defense official said that was noted early last week and by mid-week meetings had been arranged for Monday and Tuesday between the Biden intelligence transition team and the DOD intelligence agencies.

"We're moving rapidly and if they want to avoid a delay they need to go to the proper agency review teams as ... set up under the agreements that have been in place," said an official, who emphasized that any perceived delays in meetings should not be attributed to the Defense Department.

Another senior defense official noted that the meetings were arranged quickly given the amount of time it takes to deal with specific classification procedures.

In a statement, acting Defense Secretary of Defense Christopher Miller said, "The DoD and its transition leadership are fully cooperating with the Biden transition team, placing national security and the protection of the American people at the forefront of any and all discussions."

The comments from the Department of Defense came after some media outlets had reported that Biden's team was blocked from meeting with DOD intelligence agencies.

-ABC News' Luis Martinez

Moments before Trump left the White House to head to Georgia for a campaign rally for Senate Republicans, the president, in a tweet, called on Gov. Brian Kemp to “immediately ask for a Special Session of the Legislature” in his continued efforts to overturn the election.

He continued to blast local leaders, claiming that the governor's “people are refusing to do what you ask,” adding “What are they hiding.”

"But you never got the signature verification! Your people are refusing to do what you ask. What are they hiding? At least immediately ask for a Special Session of the Legislature. That you can easily, and immediately, do," the president tweeted, referring to a previous tweet from Kemp saying he had asked for a signature audit.

Kemp announced earlier Saturday that would not be attending Trump’s rally in support of GOP Sens. Kelly Loeffler and David Perdue, whose runoff elections occur in January.

The Georgia governor's communications director confirmed to ABC News that the president called Kemp Saturday morning.

-ABC News' Elizabeth Thomas

Georgia Gov. Brian Kemp responded Saturday to a tweet from Trump earlier in the day saying he will "easily & quickly win Georgia" if Kemp and the secretary of state "permit a simple signature verification."

"As I told the President this morning, I’ve publicly called for a signature audit three times (11/20, 11/24, 12/3) to restore confidence in our election process and to ensure that only legal votes are counted in Georgia," Kemp tweeted, just hours ahead of Trump's rally in the Peach State.

Trump has used his bully pulpit to slam Kemp, a longtime Trump supporter, as he has refused to echo the president’s baseless allegations of fraud in Georgia.

The president has tweeted that Kemp was "hapless" and should "overrule his obstinate secretary of state," Brad Raffensperger -- also a Republican backer of Trump -- after the latter refused to intervene to help Trump.

"The governor's done nothing," Trump said during a Fox News interview. "He's done absolutely nothing. I'm ashamed that I endorsed him."

Biden's victory in Georgia is narrow -- he's winning by 11,769 votes, according to the current results of the  requested by the Trump campaign.

But the result of the recount -- which follows an earlier  -- indicates that the outcome of the race will not change, according to Georgia's secretary of state.

The Twitter exchange comes as Trump is set to speak at a rally for Republican Senate candidates in the state -- races that will determine the balance of the Senate.

On Friday, Kemp was expected to meet Vice President Mike Pence, also in the state for a rally, on the tarmac upon his arrival in Savannah, but he could not due to a family emergency.

Kemp is not attending Trump’s rally Saturday, according to his Communications Director Cody Hall.

-ABC News' Elizabeth Thomas, Jordyn Phelps, Ben Gittleson, Olivia Rubin, Will Steakin, Quinn Scanlan, Rachel Scott and Matthew Mosk

White House coronavirus response coordinator Deborah Birx said on Friday that her role in the Biden administration remains unclear.

“I don’t know what my role will be come Jan. 20,” Birx told Rhode Island station WPRI.

Earlier this week, Biden's team had made contact with both Birx and National Institute of Allergy and Infectious Diseases Director Dr. Anthony Fauci, holding separate meetings with the two White House coronavirus task force officials.

"I was privileged to brief them on Monday," Birx said in a separate interview Friday with ABC Des Moines affiliate WOI. "I will tell you they had very good questions, very well informed questions and as a civil servant, I always stand ready to serve any administration."

ABC News reported in November that Birx expressed a desire to continue serving in a Biden administration, according to colleagues.

However, Birx has found herself in an increasingly complicated position as she combats the virus while serving a president who has ignored science and downplayed the pandemic.

Her rosy presentations from the White House podium and presence alongside Trump at news conferences this spring -- as well as her attempt to explain away Trump's suggestion in April that Americans could inject disinfectant to treat the virus -- have hurt her credibility and led to charges she has enabled the president.

-ABC News' Ahmad Hemingway and Ben Gittleson