Mike Pompeo says he has "every expectation" Russia will target US midterm elections later this year and says North Korea may have the ability to strike the United States with nuclear missiles "in a handful of months".
- Mike Pompeo says Russia has a long history of information campaigns
- CIA director defends accusations Donald Trump is unfit for office
- Says North Korea might have ability to deliver missiles within months
Russia has been accused of meddling in the 2016 US presidential election and special counsel Robert Mueller is investigating the allegations, which Moscow denies, and whether there was any collusion involving President Donald Trump's associates.
In an interview with the BBC aired on Tuesday, US intelligence chief Pompeo said Russia had a long history of information campaigns and said its threat would not go away.
Asked if Russia would try to influence the midterm elections, he said "of course. I have every expectation that they will continue to try and do that".
"But I am confident that America will be able to have a free and fair election. That we'll push back in a way that is sufficiently robust that the impact they have on our election won't be great."
He also said the Chinese posed a threat of equal concern, and were "very active" with world-class cyber capabilities.
"We can watch very focused efforts to steal American information, to infiltrate the United States with spies, with people who are going to work on behalf of the Chinese Government against America," he said.
"We see it in our schools, in our hospitals and medical systems, we see it throughout corporate America. These efforts we have to all be more focused on.
"We have to do better at pushing back against Chinese efforts to covertly influence the world."
The Kremlin, which under Russian President Vladimir Putin has clawed back some of the global influence lost when the Soviet Union collapsed, has denied meddling in elections in the West.
It says anti-Russian hysteria is sweeping through the United States and Europe.
'Clear understanding of Kim Jong Un's capability'
In the interview, Mr Pompeo also repeated his message that North Korea was close to developing missiles, which could be used in a nuclear attack on the United States.
"I think that we collectively, the United States and our intelligence partners around the world, have developed a pretty clear understanding of [North Korean leader] Kim Jong Un's capability," he said.
"We talk about him having the ability to deliver a nuclear weapon to the United States in a matter of a handful of months."
The CIA chief defended Mr Trump over accusations from a book which suggested the President was unfocused, unprepared and unfit for his office.
"It's absurd, the claim that the President isn't engaged and doesn't have a grasp on these important issues is dangerous and false," Mr Pompeo said.
Asked if Mr Trump's use of Twitter posed any national security issues, he said: "Hasn't caused us any trouble."