Rep. Nancy Pelosi isn't ruling out impeachment proceedings against President Donald Trump, depending on findings by the special counsel investigating Russia's meddling in the 2016 election.

Pelosi is set to become House speaker Thursday and told NBC's "Today" show, "we'll have to wait and see what comes" from Robert Mueller's probe of contacts between Trump's presidential campaign and Russia.

Democrats are assuming the majority in the House, where the Constitution says impeachment proceedings must begin. Pelosi previously called impeachment a "divisive activity," and Democrats were cautious about mentioning the "I'' word during the 2018 midterms for fear it would backfire politically.

But Pelosi did not shy away from it Thursday. She said, "We shouldn't be impeaching for a political reason, and we shouldn't avoid impeachment for a political reason."

It's unclear that a sitting president can be indicted. Justice Department guidelines suggest he can't. Pelosi calls it "an open discussion." She adds, "Everything indicates that a president can be indicted after he is no longer president."

Trump has denied any wrongdoing in the campaign or with his former lawyer Michael Cohen, who pleaded guilty to federal campaign finance violations.

Pelosi also talked about Trump's insistence on funding for his promised U.S.-Mexico border wall. Trump has said the government shutdown will last "as long as it takes" to get the wall funding he wants.

"How many more times can we say no?" Pelosi told Guthrie."There is no amount of persuasion he can use."

Pelosi says negotiating with Trump is difficult because he "resists science, evidence, data, truth." The California Democrat adds, "It's hard to pin the president down on the facts."

Pelosi responded to criticism from Trump that she took a trip to Hawaii over the holidays, while he canceled his planned visit to Florida because of the shutdown. Pelosi says, "The president may not know this, but Hawaii is part of the United States of America." She says she was available on 24 hours' notice.