The Senate has voted to confirm Antony Blinken as secretary of state by a 78-22 vote.

Blinken has advised Biden on foreign policy for almost two decades. Previously, he served as deputy secretary of state in the Obama-Biden administration. When serving in his capacity as national security adviser to Biden, he was present in the Situation Room during the Osama bin Laden raid, as captured by a famous photograph. Blinken was also a top staffer on the Senate Foreign Relations Committee when then-senator Biden was its chair.

As the country's top diplomat, Blinken is expected to play a pivotal role in the Biden administration's efforts to rebuild alliances and reenter international agreements like the Iran nuclear deal and the Paris Climate Agreement.

He is Biden's fourth Cabinet confirmation following Treasury Secretary Janet Yellen, Defense Secretary Lloyd Austin and Director of National Intelligence Avril Haines.

-ABC News' Conor Finnegan

Vice President Kamala Harris -- the nation's first woman vice president -- has ceremonially sworn-in Janet Yellen -- the first woman to lead the Treasury Department in its more than 230-year history.

Yellen was sworn in outside the East side of the White House facing the Department of Treasury. She is now the first person have the distinction of serving as treasury secretary, chair of the Council of Economic Advisers and chair of the Federal Reserve.

She was confirmed by the Senate in a vote of 84 to 15 on Monday evening.

Yellen was joined by her husband, George Akerlof, and son, Robert, for Tuesday's ceremony.

-ABC News' Beatrice Peterson

Sen. Rand Paul, R-Ky., on Tuesday will make a point of order to dismiss former President Donald Trump's impeachment trial in the Senate, forcing Republicans to go on the record, indicating how they might vote in a trial.

Asked by Capitol Hill reporters Monday if he would force a vote on the trial's constitutionality, Paul said, "Yes."

Then asked if he has an idea of how many of his Republican colleagues are going to support him, Paul said, "I think it'll be enough to show that you know more than a third of the Senate thinks that the whole proceeding is unconstitutional -- which will show that ultimately they don't have the votes to do an impeachment."

-ABC News' Trish Turner and Allison Pecorin

Both Senate leaders focused their floor remarks Tuesday on the Senate power-sharing agreement -- which was agreed to Monday night when Minority Leader McConnell, feeling assured that Democrats do not have the votes to overturn the filibuster rule, agreed to move forward without language explicitly guaranteeing that the rule will stay in place.

According to Majority Leader Chuck Schumer, McConnell "relented".

"I'm glad we're finally able to get the Senate up and running -- my only regret is that it took so long," Schumer said.

COVID-19 relief will now come into focus as a key priority for Democrats -- with former President Donald Trump's impeachment trial looming.

Schumer left open the possibility of using other options to act on COVID-19 priorities if Republicans will not cooperate, saying the Senate will move "without them if we must."

The whole of McConnell's speech was focused on power-sharing and the importance of the legislative filibuster -- which Republicans could use to obstruct Biden's agenda and Democrats could vote to end.

McConnell is banking on Democratic Sens. Kyrsten Sinema of Arizona and Joe Manchin of West Virgina's assurances that they will not change their minds on keeping the filibuster rule intact.

"If the Democratic majority were to attack the filibuster they would guarantee themselves immediate chaos," McConnell said.

The stalemate reflected the logistical challenges of a 50-50 Senate in which Democrats carry power since Vice President Kamala Harris, as president of the Senate, has the power to cast tie-breaking votes.

-ABC News Allison Pecorin