Vice President-elect Kamala Harris kicked off the first night of inaugural events with closing remarks on Saturday during an event titled "America United: An Inauguration Welcome Event Celebrating America’s Changemakers."

Harris noted the work that supporters did to make this moment what it is despite challenges due to coronavirus.

"I'm so excited to officially welcome you to the 59th presidential inauguration," Harris said. "We are here not only to celebrate and mark the start of a new administration, but to honor the work you have done from the primaries to the general election, right up to this very moment -- from Zoom grassroots fundraisers to union meetings on Google Meet to our drive-in rallies -- you were there every step of the way. And on the eve of this inauguration, the president-elect and I thank you for all you have done for our country; we would not be here without you."

Harris shared a message to young Americans to keep fighting and to dream with ambition. She noted that fighting for working people, rooting out systemic racism and combating the climate crisis, while strengthening democracy, are key goals for the administration.

"And I also would not be here without the generations of Americans who struggled and sacrificed to open up opportunity in our country. I stand on their shoulders. And as I've said before, while I may be the first woman to serve as vice president, I will not be the last," she said.

-ABC News' Beatrice Peterson

Vice President Mike Pence addressed the incoming Biden-Harris administration during a speech at the Lemoore Naval Air Station in Fresno, California, Saturday.

"As a new American administration prepares to take office, we do well to remember as Americans that the price of freedom is eternal vigilance, and that a free and open Indo-Pacific is essential to our prosperity, our security, and the vitality of freedom in the world," Pence said during his remarks to sailors. 

Pence urged the incoming administration to "stay the course" in the region.

"Do what we’ve done," he said. "Stand up to Chinese aggression and trade abuses. Stand strong for a free and open Indo-Pacific and put America and our freedom-loving allies first."

The Trump administration identified China as the greatest long-term threat to the U.S. The Asian nation has shown more assertiveness in the region, including expanding its military presence in the South China Sea. 

Biden has said he may keep some of Trump's tariffs in place and expand human rights sanctions, but he's also expected to take a different tact than Trump's "America First" strategy.

-ABC News' Conor Finnegan contributed to this report

Incoming White House Chief of Staff Ron Klain gave an overview of the first 10 days of the Biden-Harris administration in a memo to senior staff Saturday shared with reporters.

"President-elect Biden is assuming the presidency in a moment of profound crisis for our nation. We face four overlapping and compounding crises: the COVID-19 crisis, the resulting economic crisis, the climate crisis, and a racial equity crisis. All of these crises demand urgent action," Klain wrote. "In his first 10 days in office, President-elect Biden will take decisive action to address these four crises, prevent other urgent and irreversible harms, and restore America’s place in the world." 

The schedule is not comprehensive, Klain noted, but includes:

Jan. 20: Biden plans to ask the Department of Education to extend the pause on student loan payments and interest for Americans with federal student loans, rejoin the Paris Agreement, reverse the "Muslim Ban" (one of Trump's earliest executive orders upon taking office) and issue a mask mandate for federal property and inter-state travel. He will also "take action to extend nationwide restrictions on evictions and foreclosures and provide more than 25 million Americans greater stability."

Jan. 21: Biden plans to sign several executive actions "to move aggressively to change the course of the COVID-19 crisis and safely re-open schools and businesses, including by taking action to mitigate spread through expanding testing, protecting workers, and establishing clear public health standards." 

Jan. 22: The president-elect will direct his Cabinet agencies "to take immediate action to deliver economic relief to working families" impacted by the pandemic. 

Jan. 25-Feb. 1: Among other executive actions, memoranda and Cabinet directives, Biden plans to sign additional executive actions to address the climate crisis, as well as take steps to "strengthen Buy American provisions," reform the criminal justice system, expand health care access and "start the difficult but critical work of reuniting families separated at the border."

"Full achievement of the Biden-Harris Administration’s policy objectives requires not just the executive actions the president-elect has promised to take, but also robust Congressional action," Klain wrote. 

-ABC News' John Verhovek

House Democrats have opened an investigation into what law enforcement and the intelligence community knew about threats to the Capitol ahead of the Jan. 6 siege.

The investigation from the House Intelligence, Oversight, Homeland Security and Judiciary committees will also examine whether anyone with security clearances -- current or former National Security, Defense, Justice or Homeland Security officials -- participated in the riot.

The investigation will also examine the federal law enforcement response in the aftermath of the attack.

"The Committees will conduct robust oversight to understand what warning signs may have been missed, determine whether there were systemic failures, and consider how to best address countering domestic violent extremism, including remedying any gaps in legislation or policy," committee members wrote in a letter to the FBI, DHS and Office of the Director of National Intelligence.  

"This still-emerging story is one of astounding bravery by some U.S. Capitol Police and other officers; of staggering treachery by violent criminals; and of apparent and high-level failures -- in particular, with respect to intelligence and security preparedness," the letter later stated.

Democrats plan to request documents and briefings from administration officials as part of the investigation -- just one of several looking into the Capitol attack.

-ABC News' Benjamin Siegel