US President-elect Donald Trump has said "only 'stupid' people or fools" would dismiss closer ties with Russia.

He seemed unswayed after his classified briefing on an intelligence report that accused Moscow of meddling on his behalf in the election that catapulted him to power.

"Having a good relationship with Russia is a good thing, not a bad thing," Mr Trump said in a series of tweets.

He added: "We have enough problems without yet another one," and said Russians would respect "us far more" under his administration than they do with Barack Obama in the White House.

Mr Trump has repeatedly questioned the assessment by American intelligence agencies that the Kremlin interfered in the 2016 election, and a classified report presented to him on Friday seemed to have little changed his thinking.

The report explicitly tied Russian president Vladimir Putin to election meddling and said that Moscow had a "clear preference" for Republican Mr Trump in his race against Democrat Hillary Clinton.

But Mr Trump tweeted that the US has "enough problems" to deal with around the world and does not need testy ties with Russia on the list.

"Only 'stupid' people or fools" would oppose good relations, and he claimed that under his leadership, Russians would respect the US "far more than they do now" with Mr Obama in charge.

His approach, he suggested, might allow the adversaries to work together to solve "some of the many great and pressing problems and issues of the WORLD!"

Even as intelligences officials looked back in their reports on the election, they also made a troublesome prediction: Russia is not done intruding in US politics and policymaking.

Putin has been accused of meddling with the US election.

Immediately after the November 8 election, Russia began a "spear-phishing" campaign to try to trick people into revealing their email passwords, targeting US government employees and think tanks that specialise in national security, defence and foreign policy, the report said.

The report was the most detailed public account to date of Russian efforts to hack the email accounts of the Democratic National Committee and individual Democrats, among them Mrs Clinton's campaign chairman, John Podesta.

The unclassified version said the Russian government provided emails to the anti-secrecy group WikiLeaks even though the website's founder, Julian Assange, has denied that it got the emails it released from the Russian government.

The report noted that the emails could have been passed through middlemen.

Russia also used state-funded propaganda and paid "trolls" to make nasty comments on social media services, the report said.

Moreover, intelligence officials believe that Moscow will apply lessons learned from its activities in the election to put its thumbprint on future elections in the United States and allied nations.

The public report was minus classified details that intelligence officials shared with Mr Obama on Thursday.

In a brief interview with the Associated Press on Friday, Mr Trump said he "learned a lot" from his discussions with intelligence officials, but declined to say whether he accepted their assertion that Russia had intruded in the election on his behalf.

After finally seeing the intelligence behind the claims of the outgoing Obama administration, Mr Trump released a one-page statement that did not address whether Russia sought to meddle.

Instead, he said "there was absolutely no effect on the outcome of the election" and that there "was no tampering whatsoever with voting machines".

Intelligence officials have never made that claim.