Following his brief speech, Biden, first lady Jill Biden, Vice President Kamala Harris and second gentleman Doug Emhoff walked out to the South Portico at the White House where candles were lit and displayed on the steps for the moment of silence.

Earlier, the National Cathedral rang its bells to honor the more than 500,000 Americans who died from the coronavirus.

"I received a letter from a daughter whose father died of COVID-19 on Easter Sunday last year," Biden said before the ceremony. "She and her children, his grandchildren, enter Lent this season, a season of reflection and renewal, with heavy hearts. Unable to properly mourn, she asked me in the letter, what was our loss among so many others? Well, that's what has been so cruel."

"So many of the rituals that help us cope, that help us honor those we loved, haven't been available to us. The final rites, with family gathered around, the proper home going, showered with stories and love, tribal leaders passing out the final traditions of sacred cultures on sacred lands," he continued. "As a nation, we cannot and we must not let this go on. That's why the day before my inauguration ... I said, 'to heal -- to heal, we must remember.' I know it's hard. I promise you, I know it's hard. I remember. But that's how you heal. You have to remember."

In remarks ahead of a candlelight ceremony, Biden addressed the nation.

"Today we mark a truly grim, heartbreaking milestone: 500,071 dead," Biden said.

"That's more lives lost to this virus than any other nation on Earth. But as we acknowledge the scale of this mass death in America, remember each person and the life they lived," he continued.

"We often hear of people described as 'ordinary Americans.' There's no such thing. There's nothing ordinary about them. The people we lost were extraordinary. They spanned generations. Born in America, immigrated to America, but just like that, so many of them took their final breath alone in America," Biden said. "As a nation, we can't accept such a cruel fate. While we've been fighting this pandemic for so long, we have to resist becoming numb to the sorrow. We have to resist viewing each life as a statistic or a blur or on the news. We must do so to honor the dead, but equally important, care for the living, those they left behind -- for the loved ones left behind."

The House is one step closer to sending the White House's $1.9 trillion COVID-19 relief package to the Senate after the bill advanced through the House Budget Committee Monday. The committee favorably reported the proposal to the full House in a near-party line 19-16 vote.

"We are in a race against time," House Budget Committee Chairman John Yarmuth, D-Ky., said. "Aggressive, bold action is needed before our nation is more deeply and permanently scarred by the human and economic costs of inaction."

Republicans decried the price tag for the package and accused Democrats of using the pandemic as an excuse to pass key agenda items, including the $15 an hour minimum wage increase.

-ABC News' Benjamin Siegel

The president issued a proclamation following the U.S. recording 500,000 deaths from COVID-19 and he noted that this means more Americans have now died from the virus in one year, compared to in World War I, World War II and the Vietnam War combined.

At 6 p.m., Biden will deliver remarks on the more than 500,000 lives lost to COVID-19 and then he, Harris and their spouses will observe a moment of silence and hold a candle-lighting ceremony at sundown.

In addition, Biden ordered flags lowered to half-staff on federal property for the next five days.

Earlier Monday, White House press secretary Jen Psaki told ABC New Chief White House Correspondent Cecilia Vega that the administration is still working to undo the "inherited" circumstances of the pandemic, taking a swipe at the Trump administration.

"Our focus is on building out of the hole that we inherited," Psaki said.

-ABC News' Sarah Kolinovsky and Justin Gomez

Asked by Judiciary Chairman Sen. Dick Durbin whether the Jan. 6 insurrection was a "one-off" domestic terrorism event, Garland said he didn't think it was, citing comments by FBI Director Chris Wray who has outlined the rise in threat of domestic terrorism in recent years.

Garland said he agreed that we are currently facing "a more dangerous period" than the nation faced when he was overseeing the investigation of the Oklahoma City bombing. He said while he has no inside information about the department's investigation into the Capitol rioters, he said "it looks like an extremely aggressive and perfectly appropriate beginning to an investigation" adding it will be his first priority and first briefing upon his return to the department if he's confirmed.

Asked about the Trump Administration's child separations, Garland said the policy was "shameful" and said he would ensure cooperation from Justice Department into the committee's investigation of the policy.

"I can't imagine anything worse than tearing parents from their children and we will provide all the cooperation we possibly can," Garland said.

Garland was asked whether he will let special counsel John Durham finish his investigation, Garland said he had no information on it but has no reason from what he currently knows to believe Durham should be removed. Garland said it will be among his first briefings upon confirmation as Attorney General.

Garland declined to answer a question from Grassley about whether he will commit to defending the death sentence penalties for certain individuals like the Boston marathon bomber, noting they are pending cases.

Grassley also asked whether Garland had any discussions with Biden about the investigation into Hunter Biden.

"I have not. The president made abundantly clear in every public statement before and after my nomination that the decisions about investigations and prosecutions will be left to the justice department," Garland said. "That was the reason that I was willing to take on this job, and so the answer to your question is no."

-ABC News' Alexander Mallin