US President Donald Trump will press Russian leader Vladimir Putin on Moscow’s denial of meddling in the 2016 presidential election when the two leaders meet next month, national security adviser John Bolton said on Sunday.

Bolton said he discussed concerns about Russian meddling in the US elections with Putin during his visit to Moscow on Wednesday, citing activities targeting congressional elections coming up in November as well as the 2016 presidential contest.

“The election meddling issue was definitely something we talked about,” Bolton told the CBS “Face the Nation” program. Bolton said he brought up both the 2016 election and Russian activities in upcoming congressional elections.

Speaking about the meddling, Bolton told the “Fox News Sunday” program: “I think it’s something that we’re concerned about. That’s why the president is going to speak with him about it again.”

“I think the president will have to pursue that further and I think that’s one reason why he and President Putin need to have this conversation,” he said, adding that “Vladimir Putin is the one who makes the decisions and I think our leader needs to speak with him.”

Trump’s praise of Putin as a strong leader and his stated desire to forge better relations with Russia are of concern to critics. They fear he may cede too much during their first official summit on July 16 in Helsinki, Finland.

The Republican president said he would raise the issue of election meddling with Putin as well as Russia’s role in Syria and Ukraine.

After Trump and Putin met briefly in Vietnam in November 2017, Trump was criticized in the United States for saying he believed Putin when he denied Russian meddling.

US intelligence agencies have alleged that Russian hackers had tried to help Trump win the White House, something Russia has flatly denied. Special Counsel Robert Mueller is investigating whether Trump’s campaign worked with Moscow. Trump denies any collusion and has called the probe a “witch hunt.”

Putin last month said patriotic Russian hackers may have staged cyber attacks against countries that had strained relations with Moscow and denied state intervention – a departure from the Kremlin’s previous denials of any Russian interference.

“I’m concerned when the president tweets, you know, Russia denies they meddled in our election,” Republican US Senator Lindsay Graham told NBC’s “Meet the Press” program on Sunday. “When they say they didn’t meddle, they’re lying.

“So I’m glad the president is going to confront Putin. Show him the evidence you’ve got, Mr. President, because it’s overwhelming.”

Bolton also said he discussed Russia’s annexation of Crimea with Putin and his aides during a 90-minute meeting.

“President Putin was pretty clear with me about it, and my response was we’re going to have to agree to disagree on Ukraine,” he said. “That’s not the position of the United States.”