Washington (CNN) President-elect Donald Trump downplayed Russia's role in the election after a briefing with top US intelligence officials, even as a declassified report of their conclusions pointed definitively at Vladimir Putin.

"While Russia, China, other countries, outside groups and people are consistently trying to break through the cyber infrastructure of our governmental institutions, businesses and organizations, including the Democrat National Committee, there was absolutely no effect on the outcome of the election, including the fact that there was no tampering whatsoever with voting machines," Trump said in a statement after the meeting.

Trump also tried to defuse controversy over his criticism of the intelligence community and continued refusal to accept Moscow's actions, calling the Friday meeting "constructive" and offering praise for the senior intel officials. He said he will appoint a team within 90 days to figure out ways to stop foreign hacking.

The United States' most senior intelligence officials briefed Trump on Russian hacking during the election campaign just hours after the President-elect doubled down on his dismissal of the threat as an artificial and politically driven controversy, calling it a "witch hunt."

Trump's meeting with the intel officials took around 90 minutes at Trump Tower. A Trump spokeswoman said the officials who gave the briefing were Director of National Intelligence James Clapper, CIA Director John Brennan and FBI Director James Comey.

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A senior transition official described the meeting between Trump and intelligence community officials as "cordial," not contentious. Trump asked questions and made clear his admiration for intelligence community employees, the official added.

Based on the presentation Friday, which included new information, the official insisted that it's the transition's view that the hacking was intended to harm Hillary Clinton more than to help Trump. This official pointed to what they were told at the meeting, that the cyberactivity began in late 2015 and early 2016, before it was clear Trump would be the nominee. So, the official asked, how could the hacking be a pro-Trump operation if it began so early on.

"This was more an effort to discredit her than anything else," the official said.

The official would not weigh in on the intelligence community's main conclusion that Putin directed the hacking operation, saying it was based on classified information.

In a statement Friday accompanying the release of a declassified report on Russian involvement, the Office of the Director of National Intelligence said that the "intelligence community did not make an assessment of the impact that Russian activities had on the outcome of the 2016 election."

It added that the Department of Homeland Security concluded that "the types of systems the Russian actors targeted or compromised were not involved in vote tallying."

Democrats seethe

Trump's public refusal to acknowledge the intelligence community's conclusions drew sharp responses from Democratic lawmakers Friday. And with the release of the report, Democrats said they will renew their push for a bipartisan independent commission to investigate Russia's actions. To date, Republicans have insisted on keeping investigations within existing committees that they control.

"There must be a bipartisan, independent, outside commission to understand how Russia hacked into our democratic institutions, and to ensure it never happens again," said House Minority Leader Nancy Pelosi, a California Democrat. "Vladimir Putin's assault on American democracy was political thuggery in support of Donald Trump, and there must be consequences."

Pelosi, who had earlier called the report's conclusions "stunning," said she is co-sponsoring House legislation that was re-introduced Friday and calls for a bipartisan, independent commission. California Democratic Sen. Dianne Feinstein, formerly a longstanding member of the Senate Intelligence Committee, said she and other senators will soon introduce a similar bill.

"This issue must not be politicized -- all Americans should be outraged at Russia's actions, and we must hold them accountable," she said.

Senate Minority Leader and New York Democrat Charles Schumer said, "That any foreign power could influence an American election should send shivers down the spines of both political parties, regardless of which party benefited this time around ... We need to confront this interference head on, in an aggressive and bipartisan manner. If we don't, it'll be open season for any foreign power who wants to cause trouble in our elections."

Rep. Adam Schiff, the California Democrat and ranking member of the House Intelligence Committee, dismissed Trump's argument out of hand.

"The President-Elect's statement that the Russian hacking had 'absolutely no effect on the outcome of the election' is not supported by the briefing, report, or common sense," Schiff said in a statement.

He added that while there was no tampering with vote tallying, "it is another thing to say that the daily dumping of documents disparaging to Secretary Clinton that was made possible by Russian cyberoperations had no effect on the campaigns."

Schiff said the Putin-directed effort was "hugely beneficial to the President-Elect and damaging to the Clinton campaign, just as the Russians intended," and called on Trump to act "appropriately in the face of this clear-cut, Russian malicious activity against America. That starts by accepting the facts. The President-Elect must not obfuscate or distract, but deal honestly with the truth of what happened."

One Republican, South Carolina Sen. Lindsey Graham, took the opportunity to pressure Trump to get tougher on Moscow.

"I take his statement as an encouraging sign that he wants to push back against those who engaged in cyberattacks against our country's national security, economic and political interests," Graham said in a statement.

"More specifically, when it comes to Russia, I look forward to working with President-elect Trump to achieve those goals," added Graham, who is pushing to sanction Russia for its activities in cyberspace, Syria and against US allies in Europe. "Now is the time to throw rocks, not pebbles, and a good place for us to start would be to institute additional punishments on Russia for their cyber interference in the 2016 elections."

Russia had 'clear preference' for Trump

Shortly after Trump's statement, the intelligence community released a declassified version of the report that found Putin had ordered a campaign to influence the 2016 election with the goal of denigrating Clinton, boosting Trump and undermining public faith in the democratic process.

"We further assess Putin and the Russian government developed a clear preference for President-elect Trump," the intelligence report said.

The Russian efforts blended covert activity, including cyber operations, with overt efforts, including paying social media "trolls." The operation was just "the most recent expression of Moscow's longstanding desire to undermine the US-led liberal order," the report said.

The report shared conclusions reached in the classified version, but didn't include information that could give away sources and collection methods.

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Despite the fact that the intelligence community has never argued that the hacks swayed the outcome of the election, Trump and other Republicans have continued to emphasize that point. Intelligence leaders have been careful to stress that voting systems weren't tampered with, but they told a Senate hearing Thursday that it was impossible to assess how the hacking may have affected voters' attitudes. After lawmakers and intelligence officials expressed concern at that hearing about Trump's putdowns of the intelligence community, he praised them in his statement Friday.

"I have tremendous respect for the work and service done by the men and women of this community to our great nation," Trump said.

Former CIA chief and Defense Secretary Leon Panetta called those comments a step in the right direction for Trump.

"I pray that we get beyond this bickering and tweeting with regards to the intelligence community," he said on CNN's "The Situation Room." "And his statement today at least was a step in the right direction. He talked about having a constructive meeting, he indicated he has tremendous respect for the men and women in our intelligence community ... so I hope that he's moving in the right direction."

President Barack Obama, who last month asked the intelligence community to provide the comprehensive report on Russia's cyberactivities last month, was briefed Thursday.

Trump's muted reaction to the officials' briefing will not subdue questions about his stance on Russia. Trump has repeatedly rejected the October assessment of all 17 US intelligence agencies that Russia stole and shared emails from Democratic organizations and individuals and probed voting systems in several states.

Throughout the campaign, Trump emphasized his interest in improving relations with Moscow and his admiration for Putin, who he has praised as a strong leader who is "very smart." That praise has puzzled observers, who point to Russia's annexation of Crimea, its alliance with Syrian President Bashar al-Assad, its attempts to destabilize US allies in Europe, particularly in the Baltic states, its harassment of US diplomats, and its systematic expulsion of American Non-Governmental Organizations in Russia.

Trump has derided intelligence agencies for weeks, setting off the word "intelligence" in quotation marks to indicate his skepticism and suggesting their conclusions were politically motivated. That idea is anathema to officers who pride themselves on providing "unvarnished" and "untainted" information to policy makers, Clapper said.

California Democratic Rep. Eric Swalwell and Maryland Democratic Rep. Elijah Cummings re-introduced a bill Friday to establish a bipartisan, 12-member commission that has the support of 170 House lawmakers. The legislation calls for the commission to examine Russia's hacking as well as cyber intrusions by other nations and produce a report with recommendations to the President within 18 months.

Over 50,000 Americans have signed a petition released Friday urging Congress to create an independent commission, telling lawmakers that "regardless of whether you voted for Donald Trump, Hillary Clinton, or anyone else, Russia's attacks on our election are an attempt to degrade our democracy."

CORRECTION: An earlier version of this story misstated Nancy Pelosi's title.