(CNN) A Senate hearing on Russia policy became a platform for Democrats to hammer home the point that President Donald Trump, some of his senior officials and Republican lawmakers have been spreading a discredited conspiracy theory that Ukraine interfered in the 2016 presidential election.

That theory has been at the heart of Trump's justification for withholding aid to Ukraine in return for an investigation into Joe Biden, his chief Democratic rival in 2020 -- a move to leverage US government resources for personal political benefit that has triggered a House impeachment inquiry.

Asked if he was aware of any evidence that Ukraine interfered in the 2016 US election, Under Secretary of State David Hale said, "I'm not."

Sen. Robert Menendez, the leading Democrat on the Senate Foreign Relations Committee, then asked Hale whether Russia interfered in the 2016 election to benefit Trump.

"Yes," Hale said, "the intelligence community assessed that Russian President Vladimir Putin ordered an influence campaign in 2016 aimed at our presidential election."

And when asked whether US national security is stronger when senior officials repeat debunked conspiracy theories. Hale told the committee that "it does not serve our interests."

The exchange, one of several, came as Trump and his supporters continue to insist Ukraine interfered in the 2016 election, despite the fact that US intelligence agencies have concluded that the theory has been spread by Russian intelligence in an attempt to deflect blame from Moscow.

Secretary of State Mike Pompeo -- a former CIA director -- refused to counter the discredited Ukraine conspiracy theory on November 26, saying it was the government's "right" and "duty" to investigate all instances of election interference.

Republicans keeping debunked theory alive

The intelligence community has briefed Congress that Russia is behind the theory, yet some Republican lawmakers, most notably Louisiana Sen. John Kennedy, also insist on keeping the debunked theory alive.

"There's no question in my mind Ukraine did try to influence the election," Kennedy told CNN on Tuesday morning. "I know that I've read that the Intelligence Committee made some kind of finding, I don't know what it was," said Kennedy, a member of the Judiciary committee.

Referring to Fiona Hill, the former senior Russia official on the National Security Council who testified before the House and emphasized that the Ukraine theory is the work of Russian intelligence, Kennedy said, "I'm aware of Dr. Hill's testimony and she's entitled to her opinion."

As justification, Kennedy pointed to media reports. That seemed to prompt a mild rebuke from Utah Sen. Mitt Romney, when he left the committee hearing on a break.

"Our intelligence community and the representatives today from the Department of State indicate that there was not meddling by Ukraine in our election," Romney said.

When pressed on whether it was dangerous for some of his Republican colleagues to continue to peddle this theory, Romney demurred. "I'm not going to comment on other Senators views," he said.

But he added: "I do think that we have to adhere to the facts presented to us by our intelligence community and I know some people will look at newspaper accounts and say, gee, this is what I read in the newspaper, but you know not every article is exactly accurate and sometimes articles are being promoted by an intelligence source that is trying to push a narrative that that is not in our interest."

The political manipulations surrounding Ukraine came up between questions US policy on Russia with regard to arms control, terrorism, Syria, Moscow's increasing assertiveness toward Baltic States and its posture toward Europe. Senators also repeatedly raised questions about why the administration has failed to enforce legally required sanctions against Russia and Turkey.

But the political cloud surrounding Ukraine came up repeatedly, with lawmakers raising other aspects of Trump's actions on Ukraine. Sen. Chris Murphy, a Connecticut Democrat, explored whether administration efforts that came to light during the House intelligence committee's probe are continuing.

He asked whether Trump's personal lawyer, Rudy Giuliani, is still involved in diplomatic conversations with Ukraine. Hale, who was the highest ranking State Department official to testify before the House impeachment probe, told the committee, "No, not that I'm aware of."

New details

Hale's testimony before the House had revealed new details, including confirmation that Pompeo spoke to both Giuliani and Fox News' Sean Hannity about the attacks on former US Ambassador to Ukraine Marie Yovanovitch, who was dismissed by Trump after a smear campaign by Giuliani.

Murphy also asked the administration was still pushing Ukraine to investigate a debunked theory about Crowdstrike , a cybersecurity company that investigated Russia's hack of a Democratic National Committee server. "No," said Hale.

And Murphy asked whether it is it currently US policy toward Ukraine to request investigations into the connection between former Vice President Joe Biden's family and a company called Burisma. "No," Hale said.

Hale spoke at length about Russian misinformation and Moscow's efforts to influence the 2020 elections.

"Moscow uses digital technologies to target us and our democratic allies from within," Hale said. "These actions include election meddling, and complex, well-resourced influence operations directed by the highest levels of the Russian government, in the very heart of the Western world."

Hale said the US had provided significant foreign assistance in Europe and Eurasia, almost all of which supports "building resilience to, and increasing pressure on, Russian malign influence, in accordance with the countering Russia's influence fund."

And Hale added that, "of course, Russian behavior's not just about influencing elections. They also use social media and other cyber tools to try to sow division in our country on a whole host of issues.... We have to have continual focus on this problem."