After his final night at home before his inauguration as the 46th president of the United States, Biden is wishing Wilmington, Delaware, farewell in afternoon remarks at a "send-off event" before he heads to Washington, D.C., Tuesday afternoon.

Biden will no longer be taking an Amtrak trip from Wilmington to Washington, as he was accustomed to doing as Delaware senator, due to security concerns.

Once he's in Washington, Biden and Vice President-elect Kamala Harris in the early evening plan to speak at the Lincoln Memorial Reflecting Pool to honor COVID-19 victims -- on the same day the country may hit [400,000 deaths]( from the pandemic -- while facing a National Mall filled with 200,000 American flags.

Vice President Mike Pence arrived at the White House for his last full day in office on Tuesday morning around 11 a.m.

Pence will be leading his final White House coronavirus task force meeting at 2 p.m., according to his public schedule.

Trump and Pence met at the White House last Monday for 90 minutes, their first time speaking after the deadly attack on the U.S. Capitol.

-ABC News' Elizabeth Thomas

A defense official confirms that vetting conducted by the FBI determined two Army National Guard members have ties to far-right groups and that they have been removed from the inauguration security mission. They are currently under investigation.

Gen. Daniel Hokanson, chief of the National Guard Bureau, told NBC News Tuesday morning, “We don’t allow extremism of any type in our organization.”

At least 21,500 National Guardsmen are in Washington, D.C., the D.C. Guard confirmed to ABC News on Monday, with the preparations coming ahead of Biden’s inauguration and in the aftermath of the deadly Capitol raid conducted by Trump supporters earlier this month.

The ramp-up in the number of Guardsmen in the nation's capital means there could be four times as many American military service members in the city than there are in Iraq and Afghanistan combined.

The Department of Defense is referring questions to the Secret Service.

-ABC News' Luis Martinez and Matt Seyler

The rush of confirmation hearings for Biden’s Cabinet nominees kicked off Tuesday morning with those being vetted for top jobs in national intelligence and the heads of the Departments of Homeland Security, Treasury, State and Defense appearing before the Senate both virtually and on the heavily fortified Capitol grounds.

Senate committees will hear the cases for Janet Yellen to serve as treasury secretary, Avril Haines to serve as the director of national intelligence,  Anthony Blinken to serve as secretary of state, Lloyd Austin to serve as secretary of defense and Alejandro Mayorkas to serve as the Department of Homeland Security secretary.

ABC News has obtained a copy of Homeland Security nominee Alejandro Mayorkas' prepared opening statement ahead of his delivery, showing he's expected to call the Jan. 6 Capitol Siege "horrifying" and pledge to prevent another. If confirmed, Mayorkas would be the first Latino and immigrant in the position.

“If I should have the honor of being confirmed, I will do everything I can to ensure that the tragic loss of life, the assault on law enforcement, the desecration of the building that stands as one of the three pillars of our democracy, and the terror felt by you, your colleagues, staff, and everyone present, will not happen again,” Mayorkas is expected to say.

As Biden is sworn in on Wednesday, he will have no cabinet nominees confirmed.

By contrast, when Trump was sworn in, a GOP-controlled Senate had three nominees ready on Inauguration Day, though Senate Majority Leader Mitch McConnell at the time blamed Democrats for the low number. On then-President Barack Obama's first day in office, he had seven nominees confirmed by a Democrat-controlled Senate.

The 2021 committees are ramping up for Biden's confirmation hearings at the same time as Trump's impeachment trial is expected to start -- with Pelosi expected to send the article by the end of the week -- a challenge for the Senate, which is also reeling from the attack on the U.S. Capitol less than two weeks ago.

-ABC News' Shannon Crawford and Trish Turner

In his appearance on ABC's "This Week" Sunday, Biden’s nominee for Surgeon General Vivek Murthy said that when it comes to meeting the goal for 100 million vaccines in the first 100 days of the president's administration, there are things that could go right or wrong.

"I think President Biden fully understands there's a larger goal here, as we all do, which is that we've got to vaccinate as many Americans as possible. And that's going to take a lot of work, work dispelling this disinformation, working on the supply, increasing distribution channels," he told ABC News Chief Anchor George Stephanopoulos. "And that's some of what the vaccine plan that he announced over the last week is intended to -- to achieve."

Stephanopoulos pressed Murthy on whether there are ways to increase the supply and equitably distribute the vaccines.

"It appears, at least in these first vaccines that have gone out, they've been going largely to wealthier areas of the country, largely to whiter areas of the country," Stephanopoulos said.

"Well, it's the right question, George, because success has to be gauged not just by the number of vaccines we deliver but also by how fairly we deliver those vaccines -- how equitably we deliver them," he said in response. "What we've got to do here is not just, again, increase supply, which we can do using the Defense Production Act ... but we've also got to set up the kind of distribution channels, like mobile units, like strategically placed community vaccination centers, that can reach people who traditionally are hard to reach and don't have access to health care."

He added, "We have got to track our progress. We have got to make sure that we have data on where the vaccine is being administered, so that we can ensure that it, in fact, is being distributed equitably."