Former Director of National Intelligence James Clapper on Thursday said he saw no evidence that any entity except Russia interfered in the 2016 election, despite President Donald Trump’s equivocation on the matter.

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

Speaking at a press conference in Warsaw, Poland on Thursday, Trump declined to single out Russia for interfering in the 2016 election.

“I think it was Russia. And I think it could have been other people and other countries. It could have been a lot of people interfered,” Trump said. “I said it very simply. I think it could very well have been Russia. But I think it could well have been other countries. And I won’t be specific. But I think a lot of people interfere.”

Clapper said a reported uptick in Russian intelligence gathering in the United States “certainly fits the standard Russian pattern, which comports with their behavior going back decades.”

“I have no doubt about their stepped-up pace of intelligence collection in this country,” he said. “They’re going to stretch the envelope as far as they can to collect information and I think largely to, if I can use the military phrase, prep the battlefield for 2018 elections.”

Clapper said he has “no doubt at all” that Russia will try to interfere in the 2018 and 2020 elections.

“As long as we don’t push back with the Russians and take the necessary measures to foreclose, they are going to continue,” he said. “They could go after Republicans, which I wish people would remember. This is an assault on us, our nation, our country.”