State Dept. condemns arrests, repression in Russia

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

Biden felt like he was "coming home" after being sworn in as president Wednesday, according to the White House press secretary.

"Remember, he spent eight years here as the vice president, playing an important role as a partner to President Obama. And, you know, that was the emotion that overtook him today," Jen Psaki said during a press briefing when asked what it was like for Biden to be in the Oval Office.

The president also felt an "incredible sense of calm" and "joy" on Wednesday, she said.

"He spent the day with his family and his grandchildren and his children, and that always has an impact, I think," Psaki said.

Biden signed 15 legislative actions on his first day in office, White House press secretary Jen Psaki said during a press briefing, several of which reversed actions by the previous administration.

The president signed an executive order reversing Trump's decisions to withdraw from the World Health Organization and the Paris Climate Agreement.

Biden also put an end to the so-called Muslim Ban, "a policy rooted in religious animus and xenophobia," Psaki said, and signed a proclamation halting further funding or construction of the border wall and terminating the emergency diversion of funds for wall construction.

A broad executive order would also roll back regulatory reversals made by the Trump administration and place a temporary moratorium on all oil and natural gas leasing in the Arctic National Wildlife Refuge, the press secretary said.

Biden also sent his immigration bill to Congress. The act would provide long-term residents an opportunity to earn citizenship and "ensure that America can remain a refuge" for those fleeing prosecution, Psaki said. Biden additionally directed the secretary of homeland security to preserve the Obama-era Deferred Action for Childhood Arrivals program.

Other actions addressed the coronavirus pandemic and economic relief, including a mask mandate on federal grounds, appointing a COVID-19 response coordinator and asking relevant agencies to extend nationwide moratoriums on evictions and foreclosures and the pause on student loan payments and interests.

Biden also launched an effort to "advance racial equity and root out systemic racism from federal programs and institutions," Psaki said.