Biden, in an evening address from Wilmington, Delaware, is announcing his vaccination and economic rescue legislative package.

The ambitious $1.9 trillion proposal focuses on stimulus amid the ongoing pandemic.

Biden's plan would dedicate more than $1 trillion of the $1.9 trillion price tag for direct stimulus, officials said, while $400 billion would go toward COVID-related projects, including the nationwide vaccination program, and $440 billion toward relief for communities and businesses.

The plan includes direct payments of up to $1,400 to families in need, that when combined with the recent $600 stimulus payment would deliver on Biden's pledge to pass $2,000 of direct payments, along with a $400 weekly unemployment insurance benefit through September and a child tax credit.

-ABC News' Molly Nagle

Photos show the beginning of the process to move President Donald Trump out of the White House, as workers load boxes on to trucks.

Biden on Thursday announced his slate for new leadership at the Democratic National Committee, including former South Carolina U.S. Senate candidate Jaime Harrison to be the next chair of the DNC.

Harrison, who lost the 2020 race to GOP Sen. Lindsey Graham last year, despite breaking numerous fundraising records, will officially become DNC chair after the full committee votes on Jan. 21, the day after Biden's inauguration.

Graham congratulated Harrison on the news in a tweet earlier Thursday.

In addition to Harrison, Biden also announced the names of four DNC vice chairs, all of whom were prominent backers of his presidential campaign, including Michigan Gov. Gretchen Whitmer, who served as a campaign co-chair.

Whitmer is joined by Atlanta Mayor Keisha Lance Bottoms, Illinois Sen. Tammy Duckworth and Texas Rep. Filemon Vela as new DNC vice chairs.

House Speaker Nancy Pelosi called Harrison an "inspiring, energizing and influential" in a press release.

"As former Chair of the South Carolina Democratic Party and senatorial candidate, Jaime brings an outstanding track record of success -- from galvanizing the grassroots, mobilizing millions and shattering fundraising records -- that will be critical during this pivotal moment for our Party and Country," she added.

-ABC News' John Verhovek and Beatrice Peterson

During an unscheduled stop on Capitol Hill, Vice President Mike Pence greeted National Guardsmen and telling them that he had just come from a briefing where he heard about their efforts.

He thanked the personnel for "stepping forward for your country" to make the historic transfer of power possible.

"It's been my great honor to serve as your vice president and I want to thank you for your service," Pence said.

The vice president then spoke to individual guardsmen asking them where they are from and how long they served.

About 20,000 National Guard members are expected in Washington this week to protect the city ahead of Biden's inauguration.

"Have a safe inauguration," Pence said.

-ABC News' Elizabeth Thomas and John Parkinson

Far from a one-off event, the Jan. 6 siege at the Capitol emboldened extremists and “is very likely part of an ongoing trend,” according to a joint intelligence bulletin obtained by ABC News.

The trend involves domestic extremists exploiting lawful gatherings to engage in violence and criminal activity and the bulletin said that “very likely will increase throughout 2021.”

Targets include racial, ethnic and religious minorities along with journalists and government officials.

“Narratives surrounding the perceived success of the 6 January breach of the US Capitol, and the proliferation of conspiracy theories will likely lead to an increased [domestic violent extremist] threat towards representatives of federal, state, and local governments across the United States, particularly in the lead-in to the 20 January Presidential Inauguration,” the bulletin said.

Beyond the inauguration, the bulletin said gun control legislation, the easing of immigration restrictions and limits on the use of public land could antagonize extremists.

There is a range of groups that share what the bulletin called the “false narrative of a stolen election.”

“In-person engagement between domestic violent extremists of differing ideological goals during the Capitol breach likely served to foster connections, which may increase DVEs’ willingness, capability, and motivation to attack and undermine a government they view as illegitimate,” the bulletin said.

-ABC News' Aaron Katersky