WASHINGTON — Former White House official Fiona Hill butted heads Thursday with Republican lawmakers on the House Intelligence Committee after accusing them of echoing Russian propaganda by fomenting the "fictional narrative" that Ukraine meddled in the 2016 election.

Hill, one of the foremost U.S. experts on Russian President Vladimir Putin, appeared to take aim at Republicans on the panel, led by ranking member Rep. Devin Nunes of California, who have repeatedly questioned witnesses about alleged efforts by Ukrainians to hurt President Donald Trump during the 2016 campaign.

In her wide-ranging testimony, she also agreed with Ambassador Gordon Sondland's contention that he was operating with the White House's approval when he told Ukrainian officials they'd have to open an investigation into former Vice President Joe Biden and his son, Hunter, if they wanted an Oval Office meeting with Trump. She said it turns out Sondland was running a "domestic political errand," one that she warned him before she left the White House in July would end badly.

"I did say to him, Ambassador Sondland, 'Gordon, I think this is all going to blow up.' And here we are," she said.

Hill said during her opening statement in the impeachment testimony that "some of you on this committee appear to believe that Russia" and its spy services didn’t attack the U.S. in 2016 "and that perhaps, somehow, for some reason, Ukraine did."

"In the course of this investigation, I would ask that you please not promote politically driven falsehoods that so clearly advance Russian interests," Hill said. "I refuse to be part of an effort to legitimize an alternate narrative that the Ukrainian government is a U.S. adversary, and that Ukraine — not Russia —attacked us in 2016."

She issued a dire warning that Russian intelligence and its proxies are gearing up to interfere again in 2020 — and that the U.S. is "running out of time to stop them."

"Our nation is being torn apart," she testified.

She was chided for her comments by three Republican congressmen, Mike Turner, John Ratcliffe and Brad Wenstrup, who used their question time to criticize her, fellow witness David Holmes and the impeachment inquiry without asking them a question.

"Dr. Hill, I’m sorry, I have to say this, you say based on statements you’ve heard that some in this committee believe Russia did not conduct a campaign against this country is false," he said, before decrying the Democrats' impeachment efforts as "a coup." "Coups create division," Wenstrup said.

When Hill asked if she could respond to Wenstrup, he angrily declared that he hadn't asked a question. When Schiff allowed her to respond, she praised his remarks as "powerful" and noted that Ratcliffe and Turner had both stepped away.

"I don't believe there should be interference of any kind in our elections," she said, noting she was testifying as a non-partisan fact witness. "We need to be together again in 2020."

During his question time, Nunes presented Hill with his GOP-led report on Russian interference in the 2016 election. The document found that Russia interfered in the election but hadn't chosen sides in the race. U.S. intelligence agencies and a bipartisan Senate report found the Russians ultimately boosted the Trump campaign.

Through the five days of public impeachment inquiry proceedings against President Donald Trump, Nunes and other Republicans on the panel have suggested that Ukrainian officials meddled in the 2016 election by speaking out against then-candidate.

Hill acknowledged some Ukrainian officials had spoken negatively about Trump — some because of comments he'd made about Russia's annexation of Crimea and others because they wrongly assumed Hillary Clinton would win the election. She noted officials in other countries, including close U.S. allies, had also criticized Trump, something she said they should not have done.

That's still far different from what happened with Russia, where President Vladimir Putin had directed his military and foreign intelligence services to sow dissension, she noted. "I don't think those two things are exactly the same," she said.

Hill and Holmes, a career service officer who's stationed in Ukraine, said the Russians' goal was "chaos."

Russia’s interest “is to delegitimize the president,” Hill explained. Russia's goal in 2016 was to put whoever became president in 2016 — Trump or Clinton — “under a cloud.” It's a playbook they will run again in 2020, she warned.

Hill is the latest witness to events in the West Wing to testify publicly in the impeachment inquiry. In her earlier, private deposition, she revealed that Sondland, the ambassador to the European Union, had told Ukrainians visiting the White House that there was an agreement to grant Ukraine's president a visit if he committed publicly into investigations into the 2016 campaign and Burisma, the company Hunter Biden worked for.

She described that as part of a "shadow foreign policy" overseen by Sondland and others in her earlier testimony, but said that after watching Sondland's bombshell testimony on Wednesday, she now realizes she was wrong. Sondland had kept Trump, White House chief of staff Mick Mulvaney and Secretary of State Mike Pompeo "in the loop" about his efforts.

She said she now realizes her traditional policy work was effectively the outside policy.

"He was being involved in a domestic political errand and we were being involved in national security, foreign policy," she said.

Sondland testified that at the time he was asking Ukrainian officials to investigate Burisma he was unaware of the company's ties to the Bidens. Hill said that "is not credible to me," especially since Trump's personal lawyer, Rudy Giuliani, had done numerous interviews about the Bidens and Burisma in the spring.

She said she reported what Sondland's statement about the need for "investigations" during a July 10 meeting with Ukrainians to her boss, then-national security adviser John Bolton. He directed her to tell the National Security Council's lawyer about the exchange.

Bolton, she said, referred to Giuliani as "a hand grenade" who was "going to blow everyone up."

Hill suggested she had the same view of the former New York City mayor.

"He was frequently on television, making quite incendiary remarks about everyone involved in this. He was clearly pushing forward issues and ideas that would probably come back to haunt us. And in fact, I think that that's where we are today," she said.

Holmes testified that Sondland also complained about Giuliani during a July 26 lunch.

"At one point" during the lunch, Holmes said, "someone wondered aloud about why Mr. Giuliani was so active in the media with respect to Ukraine. My recollection is that Ambassador Sondland stated, 'Dammit Rudy. Every time Rudy gets involved he goes and f---s everything up.'”

Holmes also recounted overhearing a phone conversation between Sondland and Trump during the same lunch, which took place a day after Trump had asked Ukrainian President Volodymyr Zelenskiy to investigate the Bidens. He testified that Sondland had called Trump, who was speaking so loudly that Sondland moved the phone away from his ear.