WASHINGTON — House Speaker Nancy Pelosi on Thursday urged Congress to proceed with articles of impeachment against President Donald Trump, directing the chair of the House Judiciary Committee to start officially laying out its case.

"The president has engaged in abuse of power, undermining our national security, and jeopardizing the integrity of our elections. His actions are in defiance of the vision of our Fathers and the oath of office that he takes to preserve, protect, and defend the Constitution of the United States," she said during a news conference.

"If we allow a president to be above the law, we do so surely at the peril of our Republic. In America, no one is above the law."

Pelosi said testimony from hearings before the House Intelligence and Judiciary committees clearly showed the president withheld military aid in order to pressure the head of a foreign government to investigate a political rival.

"The president has engaged in abusive power, undermining our national security and jeopardizing the integrity of our elections," she said.

“Our democracy is what is at stake. The president leaves us no choice but to act because he is trying, once again, to corrupt the election for his own benefit."

Democrats in Congress accuse Trump of withholding military aid to Ukraine in exchange for an investigation into Joe Biden, a 2020 Democratic presidential hopeful.

The president responded on Twitter, saying his call with Ukraine's president was perfect, and Democrats are attacking him over nothing. 

Trump's campaign also weighed in to say that it's been the Democrats' goal all along of impeaching the president.

"We are less than a year away from Election Day 2020 and Democrats can't possibly explain to the American people why they want to take the decision of who should be president out of the hands of voters. But impeaching the President has always been their goal, so they should just get on with it so we can have a fair trial in the Senate and expose The Swamp for what it is," it said in a statement.

The Republican leader in the House, Minority Leader Kevin McCarthy, called the impeachment process illegitimate.

"Even this year in March, the speaker of the House said impeachment was so destructive to the nation that it had to be overwhelming, compelling, and bipartisan," he said.

This week, the House impeachment inquiry entered its second public phase. Members of the Judiciary Committee on Wednesday heard from four expert witnesses on constitutional law.

The hearing was heated, with Republicans wanting to be recognized and presenting certain motions in the hearing.

Three of the witnesses testified that Trump's actions were impeachable; the other disagreed.

The House Judiciary Committee will hold another hearing starting at 9 a.m. Monday.

Inquiry testimony has focused on a July 25 phone call between Trump and Ukrainian President Volodymyr Zelenskiy. In the conversation, Trump asked for a "favor," according to an account provided by the White House. He apparently wanted an investigation into both Democrats and Biden. Later, it was revealed that the administration was also withholding $400 million in military aid from Ukraine.

Republicans argue the money was given to Ukraine without any investigation, and there was no quid pro quo, or favor for a favor.

The White House faces a Friday deadline to decide whether it will participate in this and any future hearings.