WASHINGTON — House Speaker Nancy Pelosi on Tuesday evening plans to announce her party’s move to try to impeach President Trump — as it surfaced that she and other top Dems have been meeting privately to discuss the creation of a select committee for impeachment, according to reports.

Pelosi was huddled with Democratic House committee chairs before making the announcement.

“This is a very serious, in a class of its own, discussion about the conduct of the president of the United States,” Pelosi told an audience at The Atlantic Festival in Washington, DC, earlier Tuesday. “As soon as we have the facts, we’re ready.”

Pelosi said she would be making an announcement at 5 p.m. after meeting with her Democratic caucus at 4 p.m. The Washington Post reported that Pelosi would likely be announcing the formation of a select committee on impeachment amid private talks between leaders on the subject.

The news drew outrage — and warnings — from White House officials and other Republicans.

“Dems do nothing but weaponize politics when they should be working on behalf of their constituents,” said White House press secretary Stephanie Grisham in a tweet.

“President Trump is here in NYC working hard on behalf of our country, while the dems continue to stomp their feet & shout the word impeachment. Nothing new here.”

The chairman of the National Republican Committee, US Rep. Tom Emmer of Minnesota, added in a statement, “Make no mistake about it: backing impeachment will cost the Democrats their majority in 2020” in the House.

Pelosi said that if the facts mirrored what news reports said — that Trump pressured the Ukrainian president to look into former Vice President Joe Biden’s son’s dealings in the country and held promised military aid over his head in the meantime — “that would be wrong.” She wouldn’t go as far as calling it an impeachable offense.

“What would be an impeachable offense would be proven in an investigation,” Pelosi said.

She noted that a quid pro quo wouldn’t even need to be found. Simply interfering in the 2020 election by trying to get dirt on a political rival is by itself “not right,” the speaker said.

Trump promised on Twitter on Tuesday afternoon that a transcript of his call with his Ukrainian counterpart would be made public Wednesday.

The House speaker also revealed she had talked with Trump on the phone Tuesday morning, a conversation that was supposed to be about gun control but “segued into other things.” She wouldn’t detail to the crowd what else they talked about.

Among Democrats on the Hill, the chatter has been all about impeachment.

“The impeachment train is pulling out of the station and members who don’t have a seat are rushing to get on board,” one Democratic aide told The Post.