"There's a possibility of obstruction of justice, flirting with it, in any event, coming out of the White House," Pelosi, appearing on ABC's "The View," said about a reported discussion between President Donald Trump and Comey earlier this year about the Justice Department's investigation about Russian interference in the 2016 campaign.
Pelosi added, "I think if the President were to say he shouldn't testify, that would be very incriminating for the President."
Top White House surrogates have left open the option that Trump could invoke executive privilege to prevent Comey from testifying Thursday. White House Counselor Kellyanne Conway told NBC's "Today" on Monday that "the President will make that final decision."
The New York Times, citing two senior administration officials, reported Friday night that Trump does not plan
to invoke executive privilege, though they stressed the President could change his mind.
Trump fired Comey last month
, triggering a political firestorm. Since then multiple outlets -- including CNN -- have reported on Comey's interactions with the President, including a conversation urging him to end the probe
focused on his former national security adviser Michael Flynn. In the wake of that controversy, the Justice Department announced the appointment of a special counsel
to conduct the Russia investigation.
But Pelosi said it was too early to discuss impeachment. Pressed by liberal "View" host Joy Behar if the reports about the President pressuring the then-FBI director were grounds for impeachment, Pelosi didn't want to go there.
"When that word comes up, I always say to my colleagues in the Congress, my constituents, and people across the country what I said before: Anything you do has to be based on data, evidence, facts. So you can speculate but it's got to be the law and the facts and how they match up," Pelosi asserted.
She urged caution ahead of the blockbuster hearing this Thursday on Capitol Hill, saying, "let's all take a deep breath, let's just calm down as a country. This is a very serious matter."
Pelosi, who championed government action on climate change during her tenure as speaker of the House, decried the President's decision to withdraw from the Paris accord
, the international treaty the United States signed onto during then President Barack Obama's term.
"I think children know more about this subject than some of the people advising the President," the California Democrat said.