Democratic presidential candidate Bernie Sanders warned Russia to stay out of 2020 White House elections after U.S. officials had told him Moscow was trying to aid his campaign.

Bernie Sanders said Friday that his campaign briefed about Russian efforts to help his presidential campaign.

It intensifies concerns about the Kremlin’s role in the US presidential race.

“The intelligence community is telling us they are interfering in this campaign, right now, in 2020.

And what I say to Mr. Putin, if elected president, trust me you not going to interfere in American elections,” Sanders told reporters.

Sanders, considered the front-runner for the Democratic nomination and favored to win the Nevada caucuses on Saturday.

The Washington Post said U.S. officials had told Sanders about the Russian effort and had also informed Republican President Donald Trump and U.S. lawmakers.

However, it was not clear what form the Russian assistance took, the paper said.

According to sources, lawmakers Russia appears to be engaging in disinformation and propaganda campaigns to boost the 2020 campaigns of both Sanders and Trump.

The source, however, cautioned that the findings very tentative.

“We told that Russia, maybe other countries, going to involve in this campaign,” he told reporters.

“Look, here is the message: To Russia, stay out of American elections.”

“What they are doing, by the way, the ugly thing that they are doing – and I’ve seen some of their tweets and stuff – is they try to divide us up,” he said.

“They are trying to cause chaos. They’re trying to cause hatred in America.”