Russia and other foreign actors will try new techniques to interfere in the 2020 elections, building off the tactics they used in the 2016 and 2018 campaigns, America's top intelligence official warned Tuesday.

"We assess that foreign actors will view the 2020 U.S. elections as an opportunity to advance their interests," Director of National Intelligence Dan Coats told the Senate intelligence committee. "We expect them to refine their capabilities and add new tactics as they learn from each other's experiences and efforts."

Intelligence officials have warned consistently throughout the last several years that Russia has sought to disrupt American elections and divide the electorate against itself.

That will continue, Coats said.

But he also named other nations he felt were growing threats in this area, arguing that China could use cyber attacks against the United States to censor or suppress viewpoints it sees as "politically sensitive."

Iran, he added, has already used social media campaigns to target U.S. audiences, and will continue to do so.

Sen. Mark Warner, the top Democrat on the committee, said that the intelligence community has adapted to these perils since the 2016 campaign, although the threat continues.

"While we did see Russia continue to try to divide Americans on social media, and we saw cyber activity by unknown actors targeting our election infrastructure in 2018, the good news is that the IC did not see successful efforts to disrupt the vote, or the kind of "hack and leak" operations we saw in 2016 against the DNC and Clinton campaign," Warner said.

But Warner also said that the core problem started within the United States itself — something the intelligence community can't address.

"Let us remember that while Russia can amplify our divisions, it cannot invent them," he said at Tuesday's hearing. "When a divisive issue like the "take a knee" NFL controversy or a migrant caravan dominates the national dialogue, these are issues that can be – and are – taken advantage of by Russian trolls. Let's not make their work easier."

Coats also addressed a range of worldwide threats, repeating — as intelligence bosses do every years — that the U.S. has never faced as varied an array of dangers from so many places around the globe.

China seeks to overtake the United States, he warned. Iran seeks to continue to develop its ballistic missile capabilities.

And although North Korea's leader, Kim Jong Un, has signaled an openness to negotiate with President Trump about the regime's nuclear weapons program, Coats says the intelligence community does not believe that Kim ultimately would give up his strategic weapons.

Kim views the nuclear program as essential to his survival, Coats said. That's an awkward message from the nation's top intelligence officer as the White House prepares for a second summit with Kim and Trump somewhere in Asia next month.

Copyright 2019 NPR. To see more, visit https://www.npr.org.