Ahead of former President Donald Trump's address at the Conservative Political Action Conference in Orlando, Florida, Sunday afternoon, ABC News Chief Anchor George Stephanopoulos asked former New Jersey Governor and ABC News contributor Chris Christie about statements made by Republican leaders in recent weeks.

"Three weeks ago, you had Mitch McConnell saying the president bears responsibility for the siege.  Kevin McCarthy says the same thing.  Kevin McCarthy's at CPAC saying this is Trump's Republican Party.  Mitch McConnell says he'd vote for him in 2024," Stephanopoulos said.

"The bottom line is this, George.  You know, Donald Trump is not a departing two-term president like George W. Bush was and as a result, he's got an opportunity to come back again if he wants to.  And there are going to be some in the party who want him and there are going to be some in the party who don't," Christie said. "But what is consistent is many of the policies that were pursued over the last four years -- take aside the personality; take aside the tweets -- a lot of those policies are things that Republicans support."

The U.S. Food and Drug Administration authorized use of a third COVID-19 vaccine in the U.S., declaring the Johnson & Johnson vaccine safe and effective in adults 18 and older.

ABC News Chief Anchor George Stephanopoulos asked Dr. Anthony Fauci about hesitancy from people over its reported efficacy compared to others.

"What do you say to those who want to wait for Moderna and Pfizr?" Stephanopoulos asked.

"We have to get away from that line of thought," Fauci responded. "We have three highly efficacious vaccines. Safe and efficacious."

"If I went into a clinic and said we have JJ now, I would take the one that is available to me now," Fauci continued.

The White House released a letter Saturday from President Biden to the speaker of the House and president pro tempore of the Senate on the airstrike in eastern Syria, in his effort to keep Congress "fully informed, consistent with the War Powers Act."

"I directed this military action consistent with my responsibility to protect United States citizens both at home and abroad and in furtherance of United States national security and foreign policy interests, pursuant to my constitutional authority to conduct United States foreign relations and as Commander in Chief and Chief Executive. The United States took this action pursuant to the United States' inherent right of self-defense as reflected in Article 51 of the United Nations Charter," Biden wrote in the letter.

This comes following some bipartisan criticism the White House received over the decision to carry out the airstrike in Syria.

-ABC News' Molly Nagle

As Biden departed the White House to board Marine One Saturday afternoon, he was asked if he planned to punish Saudi Arabia’s crown prince following a U.S. intelligence report that concluded he ordered the killing of journalist Jamal Khashoggi.

Biden carefully teased an announcement but said it wouldn’t specifically pertain to Khashoggi’s murder.

He said, “there will be an announcement on Monday as to what we’re going to be doing with Saudi Arabia in general.”

The president then left the White House for Delaware.

On Friday the Office of Director of National Intelligence released a highly anticipated report on the death of Khashoggi, a Washington Post columnist and Saudi dissident who was murdered and dismembered at the Saudi consulate in Istanbul in Oct. 2018.

It revealed the U.S. intelligence community found Saudi Arabia’s Crown Prince Muhammad bin Salman approved an operation to capture or kill him.

The Saudi government has denied that that the crown prince was involved and instead blamed the death on a rogue team of government agents.

The killing has roiled the United States' longstanding ties with Saudi Arabia.

Biden said he spoke to King Salman on Thursday, one day before the report was released.

Harris visited a pharmacy in a Giant supermarket in a predominantly minority neighborhood of Washington, D.C., on Thursday in an effort to ease vaccine hesitancy on the same day she and Biden will tout reaching the 50 million-shot marker, which is halfway to their 100 million shots in 100 days goal. But on the same day of Harris' visit, there were problems with the district's website to register for vaccine appointments.

D.C. Mayor Muriel Bowser said the website issues were caused by a crush of demand after eligibility was expanded to include people with pre-existing conditions like severe obesity, asthma, liver disease and other conditions.

At the event, Harris spoke to Brenda Thompson, a D.C. resident who was about to receive her second dose, about her experience getting the Moderna vaccine, with Harris saying she needed to "take it a little slow" the day after her second dose.

Harris spoke with the store's pharmacist, Samir Balile, who told Harris he sees lines of people every day waiting for their shots, but he is concerned about hesitancy in the coming weeks.

Harris reported to him feeling some side effects after the second dose.

"The first dose, I was fine. The second dose, I thought I was fine, got up early in the morning, went to work, then midday I realized I might need to slow down a bit. Just that one day, and then it was fine, it was like nothing," Harris said.

-ABC News' Sarah Kolinovsky and John Parkinson