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

There is a preliminary plan to close the entire National Mall to the public for Inauguration Day amid security concerns, ABC News has confirmed.

The Washington Post was the first to report on the development, but The National Park Service has said it will make an announcement on the Mall following ongoing discussions with the Secret Service, the Biden Inaugural team and D.C. Mayor Muriel Bowser.

Traditionally, members of the public gather on the National Mall -- bookended by the Capitol building and Lincoln Memorial -- for viewing of the inauguration on large jumbotrons.

But the Mall's potential closure comes in the wake of a violent seige on the U.S. Capitol building last week, which left at least five people dead, and amid heightened security concerns regarding armed protests being planned ahead of Biden's inauguration on Jan. 20.

Security preparations for next week have already increased with up to 20,000 National Guard troops authorized to provide security at the Capitol and around Washington, D.C., for next week's ceremony, according to a Defense Department official.

Bowser has already warned visitors to stay away from the District for the inauguration due to threats of both the coronavirus pandemic and of violence.

Editor’s Note: A previous version of this post reported that the entire National Mall would be closed to the public for Inauguration Day amid security concerns. The text has been updated to reflect the fact that the closure is only a preliminary plan.

-ABC News' Dee Carden and Josh Margolin