"I can say definitively that it's a sufficient national security concern about Chinese meddling, Iranian meddling and North Korean meddling that we're taking steps to try to prevent it, so it's all four of those countries, really," Bolton told ABC News.
The comment is in reference to the 2018 US Congressional mid-term elections set to take place on November 6.
Since the 2016 US presidential election, Washington has been accusing Moscow of interfering in the country's internal affairs, particularly through social media. Russia has repeatedly dismissed these claims as unfounded, adding that meddling in other country’s domestic affairs contradicts its foreign policy.
READ MORE: Majority of Americans Think Trump 'Too Friendly' Toward Russia — Poll
The allegations concerning the meddling are the subject of a special probe by US Special Counsel Robert Mueller, repeatedly characterized by Trump as a "witch hunt" that has produced no evidence.
READ MORE: Shiny Thing!: Trump Suggests Russia Critics Switch Their Attention to China
Bolton About Brennan's Security Clearance Revocation
Speaking about the revocation of Brennan's security clearance, John Bolton explained that the former CIA official had failed to separate intelligence from politics.
"What I do know was when he was director of CIA, I was very troubled by his conduct, by statements he made in public and by what I thought was his politicization of the intelligence community … I think in the case, especially of a senior intelligence community official, who violates the separation between intelligence and policy, I think those would constitute grounds [to revoke security clearance]," Bolton told the ABC broadcaster, referring to Brennan.
READ MORE: Trump Slams Ex-CIA Chief Brennan as 'Political Hack Who Cannot Be Trusted'
The former CIA chief responded to Trump's move by saying that the US president made a politically motivated decision in order to silence others as Trump gets more desperate to protect himself from the investigation into Russia’s alleged meddling in the US 2016 election.
READ MORE: Ex-CIA Director Brennan Calls Trump's Denial of Collision With Russia 'Hogwash'
Brennan led the Central Intelligence Agency from 2013 to 2017 during the presidency of Barack Obama.
