The top Democrat on the House Intelligence Committee says the Obama administration missed an opportunity to issue a more 'forceful' deterrent after the Sony hack - inviting Russian cyber manipulation.

By failing to take more robust action, the U.S. could have failed to warn off other attacks, said Rep. Adam Schiff, the top Democrat on the House Intelligence Committee.

The Obama team identified North Korea as the culprit for the 'brazen cyber attack on Sony pictures, determining it was a form of payback for the mocking comedy, 'The Interview.'

Although the U.S. slapped on sanctions to the already heavily-sanctioned regime, it may not have been enough, the California Democrat told the Council of Foreign Relations Friday.

Rep. Adam Schiff, D-Calif., ranking member on the House Intelligence Committee, speaks to the Council of Foreign Relations about Russia's election interference, Friday, Feb. 16, 2018

'I think that others around the world watched that and determined that cyber is a cost-free intervention,' he said, NBC reported.

He spoke on a day deputy attorney general Rod Rosenstein announced indictments of 13 Russians that were part of a troll farm accused of meddling in the elections to benefit Donald Trump.

But Schiff also said Trump's team's willingness to embrace Russia's 'ham-handed' efforts was partly to blame.

'I'm certain that had John McCain or Mitt Romney been the nominee in 2016, they would have said, 'Russia, butt the hell out,'' Schiff said. 'But that's not who Donald Trump was.'

House Intelligence Ranking Member Adam Schiff (D-CA) speaks at the Council On Foreign Relations with Andrea Mitchell, Chief Foreign Affairs Correspondent at NBC News on February 16, 2018 in Washington, DC

At the time, the Obama administration took what it said was an unprecedented step of naming North Korea as the culprit, the Washington Post reported at the time.

Democrats on the House Intelligence Committee are 'very close' to reaching agreement with the FBI and Department of Justice on redactions to a memo that seeks to rebut assertions of bias in the probe of U.S. President Donald Trump's ties to Russia, the panel's top Democrat said on Friday.

'I think we're very close to reaching agreement on it,' Representative Adam Schiff said during an appearance at the Council on Foreign Relations think tank. 'I think we resolve that very soon, so we can release this.'

Trump on Feb. 9 blocked release of the classified memorandum. On Twitter the next day, he said the document was 'very political and long' and must be 'heavily redacted' to protect sensitive information.

Deputy Attorney General Rod Rosenstein, speaks to the media with an announcement that the office of special counsel Robert Mueller says a grand jury has charged 13 Russian nationals and several Russian entities, Friday, Feb. 16, 2018

Trump earlier cleared the release of a memo drafted by Intelligence Committee Republicans that alleged partisan bias in the securing of an electronic surveillance warrant on Trump campaign aide Carter Page. The president did so despite opposition from the Justice Department and the Federal Bureau of Investigation.

Democrats said the Republican document mischaracterized highly classified information and was intended to discredit the probe by Special Counsel Robert Mueller into potential collusion between the Trump campaign and Russia during the 2016 election.

'I hope we never go down this memo path again,' Schiff said of the process. 'I think my colleagues in the GOP recognize it was a big mistake.'