In a very rare move, the State Department organized a press gaggle with Secretary of State Antony Blinken, creating an opportunity for him to address the recent Washington headlines.

ABC News asked Blinken for his reaction to President Biden's decision not to seek another term and whether he saw Vice President Harris as an able replacement.

"As you all know, I don't engage in politics," Blinken began, but said he has known Harris for more than a decade and said he had been able to "observe her very closely in the situation room, in the Oval Office, around the world as a leading voice for American foreign policy."

Though the secretary did not explicitly endorse Harris, he extolled her leadership during foreign engagements, citing her work in East Asia and also claiming she was "deeply engaged in the Middle East and trying to find a peaceful path forward" and “helping to drive investment in countries in our own hemisphere so people have opportunity in the countries that they come from so they don't have to make the hazardous journey to the United States."

Blinken continued: "What I've observed is someone that asks time and again the penetrating questions, who cuts to the chase, and is intensely focused on the interests of the American people and making sure our foreign policy is doing everything it can to advance those interests."

Vice President Harris' perceived lack of experience in foreign policy has clouded her campaign. While in office, she has spent just three days in the Middle East and four days in Latin America. Still, the secretary rejected the notion that it wasn't her forte.

"My observation is she is a very strong, very effective and deeply respected voice for our country around the world. When she speaks, she speaks on behalf of the United States," Blinken said.

-ABC News' Shannon K. Kingston

The Las Vegas Metropolitan Police Department began shutting down roads leading to UMC Hospital last week when President Biden took ill in Vegas, according to the department.

"The Las Vegas Metropolitan Police Department was notified that President Joe Biden was sick on July 17th during his visit to Las Vegas. We did not know the nature of his illness. As a precaution, LVMPD proactively began to shut down roads leading to UMC Hospital. The Secret Service then advised LVMPD the President was going directly to Harry Reid International Airport and would be leaving Las Vegas," the department told ABC News.

Biden tested positive for COVID on Wednesday, following a campaign event in Las Vegas, the White House said. He has been self-isolating in Rehoboth, Delaware.

-ABC News' Josh Margolin and Alex Stone

The vetting of potential running mates for Harris has already begun, according to a source briefed on the process.

"The horse has left the barn," the source said.

The campaign does not see Aug. 7 as a deadline -- a date that marks the end of the planned virtual roll call, according to the source. The vice presidential pick is unlikely to be finalized by then.

The source said these four individuals have all been asked to submit materials: Arizona Sen. Mark Kelly; Govs. Josh Shapiro of Pennsylvania; Roy Cooper of North Carolina and Andy Beshear of Kentucky.

But that list is "not exhaustive" -- in other words, there may be another name or two, the source added.

-ABC News' Jonathan Karl

President Biden will deliver remarks about his decision to drop out of the 2024 race on Wednesday.

"Tomorrow evening at 8 PM ET, I will address the nation from the Oval Office on what lies ahead, and how I will finish the job for the American people," Biden wrote on X.

Biden announced his decision to not seek reelection in a letter addressed to his "fellow Americans" that he posted on social media on Sunday.