A spokesperson for the U.S. Army confirmed that there will be 25,000 National Guardsmen in the nation’s capital to aid with security for Biden’s inauguration.

“The Defense Department has agreed to provide up to 25,000 service members to support the Presidential Inauguration National Special Security Event federal law enforcement mission and security preparations, as led by the U.S. Secret Service,” the spokesperson said. “The Department of the Army and the National Guard Bureau are working on a sourcing solution now to support this request.”

-ABC News’ Luis Martinez

The FBI, DHS, Secret Service and U.S. Capitol Police, along with several local law enforcement agencies, have issued an extensive "threat assessment" surrounding Wednesday's inauguration.

It covers a range of threats surrounding the inauguration, including not only physical threats from domestic terrorists but also influence campaigns from Russia, China and Iran stemming from the Capitol siege. It even covers physical threats from drones.

The memo says domestic extremists is the “most likely” threat to the inauguration, citing recent incidents of ideologically motivated violence, including the deadly mob at the U.S. Capitol building.

Regarding foreign concerns, the assessment said that since the incident at the Capitol, “Russian, Iranian, and Chinese influence actors have seized the opportunity to amplify narratives in furtherance of their policy interest amid the presidential transition.”

“We have not identified any specific, credible information indicating that these actors intend to explicitly commit violence,” it added. “Furthermore, we have not identified any specific, credible cyber threat to critical infrastructure supporting the upcoming Presidential Inauguration nor a specific credible cyber threat to military or law enforcement personnel supporting the event."

The memo did say, however, that Russian state media has “amplified themes related to the violent and chaotic nature of the Capitol Hill incident, impeachment of President Trump, and social media censorship.”

Iranian state media has “continued to stoke claims that President Trump encouraged and incited the violence, as well as calls to invoke the 25th amendment,” the memo added. It has also “amplified perceived concerns related to President Trump’s mental health and the prospect of other risky actions he could take before leaving office.”

Finally, it noted that Chinese media has “seized the story to denigrate US democratic governance -- casting the United States as broadly in decline -- and to justify China’s crackdown on protestors in Hong Kong."

Lastly, the memo warned that drones could disrupt law enforcement operations at the inauguration, though it added that it does not have “specific, credible information” indicating malicious actors have plans to use unmanned aircraft systems to target the event.

-ABC News’ Mike Levine

Vice President Mike Pence spoke with Vice President-elect Kamala Harris on a call Thursday, sources familiar with the call told ABC News.

The news was first reported by the New York Times.

-ABC News’ Molly Nagle, Justin Gomez and Katherine Faulders

Sources told ABC News that Trump has requested a large sendoff hours before President-elect Biden takes the oath of office Wednesday.

Sources say Trump plans to depart the White House next Wednesday morning, choppering via Marine One to Joint Base Andrews where he is expected to give remarks to supporters and departing members of his administration.

Sources add that Trump has requested the event to have a "military-like feel" though details are still not finalized. The president will then fly down to his Mar-a-Lago club in Florida onboard Air Force One with a small number of staffers who will be part of his post-presidency operation, according to the sources.

-ABC News’ John Santucci and Katherine Faulders

Expecting the article to pass the House later Wednesday, Speaker Nancy Pelosi is planning to send the article of impeachment over to the Senate next week, according to a source involved in the Democratic leadership deliberations.

This would leave the Senate no choice but to immediately move towards a trial. The exact timing will depend on whether Majority Leader Mitch McConnell decides to call the Senate back in session early -- which he's said he wouldn't do. Under Senate rules, the Senate cannot officially receive any message or bill or resolution from the House unless the Senate is in session, and the chamber is not scheduled to be back until Jan. 19.

But in preparation for that time, Pelosi has named nine members to serve as impeachment managers to argue the case in the Senate to remove Trump from office over his role in last week’s Capitol riot.

Rep. Jamie Raskin, D-Md., a former constitutional law professor who co-authored the article and whose family was present at the Capitol last Wednesday, one day after burying Raskin's son who took his own life, will serve as the lead impeachment manager.

The other managers -- one of rarest assignments for a House member -- are Democratic Reps. Diana DeGette, Colo., David Cicilline, R.I., Joaquin Castro, Texas, Eric Swalwell, Calif., Ted Lieu Calif., Joe Neguse, Colo., Madeleine Dean, Pa., and Del. Stacey Plaskett, Virgin Islands.

"It is their constitutional and patriotic duty to present the case for the President’s impeachment and removal. They will do so guided by their great love of country, determination to protect our democracy and loyalty to our oath to the Constitution," Pelosi said in a statement Tuesday night.

The impeachment managers are a different set from those tapped by Pelosi one year ago for Trump’s first impeachment trial -- then led by Rep. Adam Schiff, D-Calif. During that effort, managers argued the case to remove Trump for pressuring Ukraine’s president to promise to investigate Biden and his son, Hunter.

-ABC News' Jonathan Karl and Chad Murray