State Dept. condemns arrests, repression in Russia

Vice President Kamala Harris addressed the public for the first time since taking the oath of office during the "Celebrating America" inaugural program Wednesday night and she echoed Biden's call for unity and overcoming adversity.

"In many ways, this moment embodies our character as a nation. It demonstrates who we are," Harris said. "Even in dark times, we not only dream, we do. We not only see what has been, we see what can be. We shoot for the moon, and then we plant our flag on it. We are bold, fearless, and ambitious. We are undaunted in our belief that we shall overcome, that we will rise up. This is American aspiration."

The vice president referenced Abraham Lincoln's work with land grant colleges and the transcontinental railroad during the Civil War and Martin Luther King Jr.'s fight for racial justice during the Civil Rights Movement as aspirational moments.

"American aspiration is what drove the women of this nation throughout history to demand equal rights and the authors of the Bill of Rights to claim freedoms that had rarely been written down before," she said. "A great experiment takes great determination. The will to do the work and then the wisdom to keep refining, keep tinkering, keep perfecting." 

This "same determination," she continued, "is being realized in America today," through the work of scientists and parents nurturing the next generation of educators and innovators. 

"This, too, is American aspiration," she said. "This is what president Joe Biden has called upon us to summon now. The courage to see beyond crisis, to do what is hard, to do what is good, to unite, to believe in ourselves, believe in our country, believe in what we can do together."

Former presidents Bill Clinton, George W. Bush and Barack Obama highlighted the importance of a peaceful transfer of power in a new video message set to air Wednesday night, ABC News confirmed.

The video, organized by the inaugural committee, features a conversation with the leaders about upholding democracy and staying civically engaged.

The three were the only former presidents at the inauguration ceremony. Jimmy Carter was unable to attend and Donald Trump left the White House ahead of the swearing-in.

-ABC News' Cecilia Vega and Mae Joo

The president continued to stress unity and optimism despite the challenges the U.S. faces during the inauguration's "Celebrating America" program Wednesday night.

"This is a great nation. We're a good people. And overcoming the challenges in front of us requires the most elusive things in a democracy -- unity," Biden said during live remarks from the Lincoln Memorial, after being introduced by host Tom Hanks.

"It requires us to come together in common love that defines us as Americans," he continued. "America's story depends not on any one of us, not on some of us, but all of us. On we, the people. That's the task before us." 

He described this moment -- confronted with a "pandemic, economic crisis, racial injustice, a climate crisis, and threats to our very democracy" -- as one that asks more of Americans, and said he believes the country will rise to the occasion.

"You, the American people are the reason why I've never been more optimistic about America than I am this very day," Biden said. "There isn't anything we can't do if we do it together."

Kamala Harris will not immediately move into the vice president's residence at the Naval Observatory, an aide confirmed to ABC News.

The unspecified delay is to "allow for repairs to the home that are more easily conducted with the home unoccupied," the aide said.

The repairs are to replace the liners in the chimneys "and other household maintenance," the aide said.

-ABC News' Benjamin Siegel