Pelosi and the Democrats are considering swift impeachment - as soon as next week - in response to the deadly siege of the U.S. Capitol by a pro-Trump mob that shocked the nation and the world
"We must take action," Pelosi declared on a conference call.
She said she had spoken with Gen. Mark Milley "to discuss available precautions for preventing an unstable president from initiating military hostilities or accessing the launch codes" for nuclear war. She said Milley assured her longstanding safeguards are in place.
The president has sole authority in the U.S. government to order the launch of a nuclear weapon, but a military commander could refuse the order if it were determined to be illegal.
Trump has been making no such threats, and he is to leave office Jan. 20 when Democrat Joe Biden is sworn in. But top lawmakers are sounding alarms that the president could do great damage on his way out.
"This unhinged president could not be more dangerous," Pelosi said of the current situation.
A person granted anonymity to discuss the private call said Pelosi also discussed other ways Trump might be forced to resign. And if he were to be impeached by the House and convicted by the Senate, he might also be prevented from running again for the presidency in 2024 or ever holding public office again. He would be only the president twice impeached.
Conviction in the Republican Senate at this late date would seem unlikely. But it's a measure of his uncomfortable position that fewer Republicans are speaking out against his removal.
One Trump ally did. Republican Minority Leader Rep. Kevin McCarthy of California said "impeaching the President with just 12 days left in his term will only divide our country more."
McCarthy said he reached out to Biden and plans to speak with the Democratic president-elect about working together to "lower the temperature."
The final days of Trump's presidency are spinning toward a chaotic end as he holes up at the White House, abandoned by many aides, leading Republicans and Cabinet members. He was tweeting again after his Twitter account was reinstated, reverting to an aggressive statement that his supporters must not be "disrespected" after he sent out a calmer Thursday video decrying the violence.
Calls are mounting for legal action following the Capitol attack, in which one protester was shot to death by Capitol police and Capitol police officer Brian Sicknick died. Three other people died from "medical emergencies" during the demonstration.
Strong criticism of Trump, who urged the protesters to march to the Capitol, continued unabated.
"Every day that he remains in office, he is a danger to the Republic," said Rep. Adam Schiff, D-Calif.
Schiff, who led Trump's impeachment in 2019, said in a statement that Trump "lit the fuse which exploded on Wednesday at the Capitol."
Articles of impeachment are expected to be introduced on Monday, with a House vote as soon as Wednesday, according to a person familiar with the planning and granted anonymity to discuss it.
Pelosi and Democratic Senate leader Chuck Schumer have called on Vice President Mike Pence and the Cabinet to invoke the 25th Amendment to to force Trump from office. It's a process for removing the president and installing the vice president to take over.
Biden's transition spokesman Andrew Bates has said the president-elect is preparing to take office and "will leave it Vice President Pence, the Cabinet and the Congress to act as they see fit."
But action by Pence or the Cabinet now appears unlikely, especially after two top officials, Education Secretary Betsy DeVos and Transportation Secretary Elaine Chao suddenly resigned in the aftermath of the violence at the Capitol and would no longer be in the Cabinet to make such a case.
Trump had encouraged loyalists at a rally Wednesday at the White House to march on the Capitol where Congress was certifying the Electoral College tally of Biden's election.
Pelosi discussed the prospect of impeachment with her leadership team Thursday night, hours after announcing the House was willing to act if Pence and other administration officials did not invoke Section 4 of the 25th Amendment - the forceful removal of Trump from power by his own Cabinet.
Rep. James Clyburn, the No. 3 House Democrat, told CNN: "Everyone knows that this president is deranged." One leading Republican critic of Trump, Sen. Ben Sasse of Nebraska, said he will "definitely consider" impeachment.
Schumer said he and Pelosi tried to call Pence early Thursday to discuss the 25th Amendment option but were unable to connect with him.
Most Democrats, and many Republicans, put the blame squarely on Trump after swarms of protesters bearing Trump flags and clothing broke into the Capitol and caused destruction and evacuations.
Three Democrats on the House Judiciary Committee began Thursday to circulate articles of impeachment. Reps. David Cicilline of Rhode Island, Jamie Raskin of Maryland and Ted Lieu of California wrote in the articles that Trump "willfully made statements that encouraged - and foreseeably resulted in - imminent lawless action at the Capitol."
The House impeached Trump in 2019, but the Republican-led Senate acquitted him in early 2020.
Pelosi said "a threshold was crossed of such magnitude" that Trump should not be allowed to make any decisions.
During a new conference Thursday, she challenged several Cabinet members by name, including Secretary of State Mike Pompeo and Treasury Secretary Steve Mnuchin.
"Do they stand by these actions?" Pelosi asked. "Are they ready to say that for the next 13 days this dangerous man can do further harm to our country?"
Pence has not publicly addressed the possibility of invoking the 25th Amendment.
Associated Press writers Alan Fram and Alexandra Jaffe contributed to this report.