House Republican Conference Chair Liz Cheney -- the No. 3 Republican in the House and highest-ranking woman in the Republican Party -- has announced she will vote to impeach Trump for inciting an insurrection at the Capitol.

"Much more will become clear in coming days and weeks, but what we know now is enough," she said in a statement. "The President of the United States summoned this mob, assembled the mob, and lit the flame of this attack. Everything that followed was his doing. None of this would have happened without the President. The President could have immediately and forcefully intervened to stop the violence. He did not."

"There has never been a greater betrayal by a President of the United States of his office and his oath to the Constitution," she said.

Her announcement follows Republican Rep. John Katko of New York becoming the first House Republican to say he will support House Democrats' efforts to remove Trump from office through impeachment.

Republican Rep. John Katko of New York has released a statement saying he will vote to impeach Trump -- becoming the first Republican to publicly voice an expected vote to remove the president from office.

Katko joins at least 218 House Democrats who have signed onto a resolution charging Trump with inciting an insurrection. A House vote could happen as early as Wednesday, one week before Biden's inauguration at the Capitol.

“To allow the president of the United States to incite this attack without consequence is a direct threat to the future of our democracy,” Katko said in the statement. “For that reason, I cannot sit by without taking action. I will vote to impeach this president."

No House Republicans voted to impeach Trump in 2019.

-ABC News' Benjamin Siegel

The first confirmation hearing for one of Biden's Cabinet picks is officially on the Senate schedule for the day before his inauguration -- which is also the earliest day the Senate is likely to accept an impeachment article against Trump from the House.

Department of Homeland Secretary nominee Alejandro Mayorkas' hearing will be at 10 a.m. on Tuesday, Jan. 19, the Senate Homeland Security and Governmental Affairs Committee announced Tuesday.

In the wake of the siege on the Capitol, the incoming Biden administration is making a push to prioritize confirmations for national security nominees, so those officials may assume their roles as early as next week.

Traditionally, the Senate has confirmed national security nominees on Inauguration Day, and did so for Department of Homeland Security secretary nominees in both 2009 and 2017.

Capitol Police have added new security measures to the House of Representatives -- requiring that all members and staff go through metal detectors before they enter the chamber, according to a new memo sent to offices by the acting House Sergeant at Arms.

The memo comes ahead of a vote Tuesday evening on a resolution pressing Vice President Mike Pence to mobilize the Cabinet and invoke the 25th Amendment to remove Trump from office.

Currently, visitors and staff are screened when they enter the Capitol building, but members of Congress are not. There are already metal detectors in place for visitors to the House galleries, which had been shuttered since March because of the pandemic.

Several lawmakers continue to worry about their safety in the wake of last week's Capitol riot -- and Democrats in control of the chamber have expressed concerns about some GOP colleagues and their alleged connections to the organizers. Some Republicans, most notably Rep. Lauren Boebert, R-Colo. have been outspoken about carrying weapons around the Capitol.

"Failure to complete screening or the carrying of prohibited items could result in denial of access to the Chamber," acting Sergeant at Arms Timothy Blodget wrote in the memo.

-ABC News' Benjamin Siegel and Mariam Khan

While House Democrats take action to remove Trump from office after he encouraged supporters to march on Capitol Hill last week.

Trump on Monday plans to award the Presidential Medal of Freedom -- the nation's highest civilian honor -- to GOP Rep. Jim Jordan of Ohio, his longtime defender, in a closed event, something not the event not mentioned on his schedule, a White House official said. Later in the week, he's expected to bestow the same honor on New England Patriots head coach Bill Belichick.

Sources told ABC News over the weekend the White House is building out a week of programming to highlight Trump’s record over the dwindling days of his administration, despite amplified calls for Trump to resign or risk facing a second impeachment. Appearing to dismiss those calls, Trump has a trip planned for Tuesday to Texas to showcase the border wall he's pushed hard for, and is expected to host events in the next week to highlight what sources say are the administration's achievements in areas including foreign affairs, business and pandemic response.

The president was angry for much of this past weekend -- mostly about Twitter permanently suspending his account on Friday, according to sources who have spoken directly to Trump. Sources said the president is expected to depart Washington before Biden takes the oath of office on Jan. 20.

While Biden said last week it’s a "good thing" Trump isn’t attending his inauguration, he hasn’t said whether he supports impeaching Trump, deflecting that decision to Congress instead. Biden's said he wants the incoming Congress to focus on his Cabinet nominations and pandemic relief from the onset, but an impeachment trial in the Senate risks preempting the rest of its business.

On Monday, Biden is slated to meet with transition and economic advisors and will publicly receive the second dose of the COVID-19 vaccine from Wilmington, Delaware, in the afternoon.

-ABC News Chief White House Correspondent, John Santucci and Katherine Faulders