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Story highlights

Clapper led the intelligence community through the end of Obama's term

He rebutted Trump's assertion that others besides Russia attempted to influence the election

(CNN) —  

The former top US intelligence official on Thursday disagreed with President Donald Trump’s claim that foreign actors besides Russia may have attempted to influence the 2016 presidential election.

Former Director of National Intelligence James Clapper, in an interview with CNN’s Jim Sciutto on “The Situation Room,” said he remains confident in the intelligence community assessment accusing Russia of attempting to bolster Trump’s candidacy – and that he knew of no evidence pointing anywhere else.

“As far as others doing this, boy, that’s news to me,” Clapper said. “We saw no evidence whatsoever that it was anyone involved in this other than the Russians.”

Speaking to reporters in Poland ahead of the G-20 summit, Trump he thought Russia was behind the efforts, but asserted that “it could have been other people in other countries.” Trump seemed to dismiss the strength of the intelligence community assessment, saying “mistakes have been made” with regard to intelligence and noting the US intelligence community’s erroneous claim that Iraq under Saddam Hussein had weapons of mass destruction – a report that the Bush administration used to make a case for war.

Clapper called the Iraq assessment a “big mistake” and said things had changed since then in the intelligence community to prevent something like that from happening.

“I remember it because my fingerprints were on it,” Clapper said of the 2002 assessment. “That was 15 years ago. The intelligence community has done a lot of things to make sure that never happens again.

Trump also said the Russia report only came from three or four agencies, knocking some news outlets for wrongly saying it had come from all 17.

Clapper said he was not sure where the 17 reference in media reports had come from and explained the three agencies – CIA, FBI and NSA – as well as his office handled the matter alone because they were the ones that could contribute relevant intelligence and the sources involved were highly sensitive. Further, he said they were working with a short timeline due to then-President Barack Obama’s instruction that the report come before the end of his presidency.

In early January, the DNI issued a declassified version of the intelligence community assessment. It pointed to Russia as being behind hacks of Democratic Party officials and attempts to spread propaganda online to harm Hillary Clinton’s campaign.

Russia has denied any involvement.

Over the months, Trump’s responses have varied and his latest comments, one day prior to his scheduled sit-down with Russian President Vladimir Putin in Europe, broke again with the repeated public assertions of current and former intelligence officials that Russia was to blame.

Clapper said Trump not taking a stiff line on Russian interference encourages Putin to “keep doing what he’s doing,” and said a CNN report on US officials noting increased Russian spying reinforced his belief on the matter.

“As long as we don’t push back with the Russians and take the necessary measures to foreclose, they’re going to continue,” Clapper said.