US president-elect Donald Trump has said that hacking by foreign powers did not affect the final outcome of the November presidential election, after being briefed on an intelligence report blaming Russia's Vladimir Putin for a cyber campaign to keep Hillary Clinton out of the White House.

"While Russia, China, other countries, outside groups and people are consistently trying to break through the cyber infrastructure of our governmental institutions, businesses and organisations including the Democrat National Committee, there was absolutely no effect on the outcome of the election," Trump said in a statement.

Trump met the heads of the Office of the Director of National Intelligence, the Central Intelligence Agency, the Federal Bureau of Investigation and the National Security Agency in New York on Friday, on their newly completed report into Moscow's alleged interference.

READ MORE: Trump pushes back against Russia hacking investigation

In a separate post on social media late on Friday, Trump blamed the Democratic National Committee for allowing hackers into its computer systems.

"Gross negligence by the Democratic National Committee allowed hacking to take place. The Republican National Committee had strong defense!"

Gross negligence by the Democratic National Committee allowed hacking to take place.The Republican National Committee had strong defense! — Donald J. Trump (@realDonaldTrump) January 7, 2017

The new declassified report, released by US intelligence officials following the meeting with Trump, said Putin "ordered" a campaign to influence the 2016 election.

It goes on to say that Kremlin developed a clear preference for Trump and hacked targets including both major political parties to help him.

The strategy encompassed covert tactics, such as cyberattacks and paying social media users, as well as overt efforts to target US government employees, think-tanks and NGOs.

The report also warned that Moscow will try to influence other elections of US allies.

'We are on the same team'

After the briefing, Vice President-elect Mike Pence addressed reporters outside of Trump Tower, in New York, about the report, vowing that the government would take an "aggressive action" to combat cyberattacks, "and protect the security of the American people from this type of intrusion in the future".

Al Jazeera's Alan Fisher, reporting from Washington DC, said the report strengthens calls from US political leaders to step up its cyber security, and to impose more sanctions against Russia.

"For a very long time, Donald Trump had been saying there is no evidence that the Russians are involved in the hacking," Fisher said, adding that Trump will have to decide on sanctions against Russia when he assumes the presidency.

Top Democrats have also been calling on the US to develop a robust cyber strategy to protect democracy.

Meanwhile, US president Barack Obama has reminded his successor that "we're on the same team," after the release of the report.

"One of the things I am concerned about is, the degree to which we've seen a lot of commentary lately where there are Republicans or pundits or cable commentators who seem to have more confidence in (Russian president) Vladimir Putin than fellow Americans because those fellow Americans are Democrats. That cannot be," Obama said in an interview with ABC News.

"We have to remind ourselves we're on the same team. Vladimir Putin's not on our team," Obama added in the interview, which is to be broadcast in full on Sunday.