Donald Trump’s national security advisor John Bolton has said he warned Moscow against meddling in US elections ahead of the 2018 midterms elections in November.

Mr Bolton told reporters he has “made it clear” the US won’t accept election meddling during a news conference hours after a meeting with Russia’s Nikolai Patrushev at the US mission in Geneva.

Mr Bolton’s meeting was a follow-up to Mr Trump’s summit with Russian President Vladimir Putin in Helsinki last month.

“I made it clear we wouldn’t tolerate (election) meddling in 2018 and we were prepared to take necessary steps to prevent it from happening,” he said.

Twelve Russian officials have since been charged as a result of special counsel Robert Mueller’s probe into whether Russia meddled in the 2016 US presidential election.

“I’m going to make sure that they understand how strongly we feel about this,” Mr Bolton told the Associated Press. He added he would “tell them how firm the position of the US is that there is no election meddling.”

When asked if there would be consequences for possible future meddling, Mr Bolton told the AP the “focus” would be on ensuring it doesn’t happen again. He added, however, that there wouldn’t be “new sanctions if there’s no further interference”.

The Trump administration had imposed new sanctions against Russia for Moscow’s alleged election interference. Mr Putin has called the sanctions “counterproductive and senseless”.

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During the press conference, Mr Bolton said he “might have had a joint statement” with Mr Patrushev but they weren’t able to reach an agreement surrounding election meddling.