"You'll be the first to know when we announce that we're going over there," she told reporters.
The House managers who act as prosecutors, Pelosi said, are "solemnly and prayerfully preparing for the trial, which they will take to the Senate."
She spoke two days after the House approved a charge of "incitement of insurrection" for Trump's role in the storming of the Capitol on Jan. 6.
"Justice is called for," she said of the Capitol assault. "At the same time we are in transition," referring to President-elect Joe Biden's pandemic relief package he unveiled Thursday evening.
Trump is set to leave office next Wednesday at noon, when Biden will take over.
The speaker also announced that she's asked retired Lt. Gen. Russel Honore - who helped coordinate the military relief efforts after Hurricane Katrina - to lead an "immediate review" of security failings at the Capitol - reviewing security infrastructure, the interagency process and command and control.
"We must subject this whole complex to scrutiny," she said. "We must be very dispassionate in how we make decisions going forward," she continued. "Security, security, security."
"We take an oath to protect and defend the Constitution and our democracy and that is what we will do," she said.
Asked about the role members of Congress may have played in the riot, Pelosi said they would be held accountable.
"If it in fact it is found that members of Congress were accomplices to this insurrection, if they aided and abetted the crime, there may have to be actions taken beyond the Congress in terms of prosecution," she said.
"I find this to be a very emotional time," she also said, citing "so many disgusting images," but singling out a video that showed one Trump rioter wearing a shirt with "Auschwitz" emblazoned on it.
"To see this punk with that shirt on," she said angrily, "and his anti-Semitism."