NEW YORK -- Longtime Republican operative and Trump confidant Roger Stone told CBS News Sunday an “exchange” he had with Guccifer 2.0. -- an individual involved in hacking Democratic National Committee emails -- was “innocuous” due to its and timing and because he was unaware at the time of the “exchange” of allegations that Guccifer 2.0 has ties to Russia.

Stone told The Washington Times Friday that he had a private Twitter exchange last year with “Guccifer 2.0,” an online persona. He said it was “so perfunctory, brief and banal” that he had forgotten about it.

Last summer, Guccifer 2.0 posted emails stolen from Democrats. U.S. officials believe Guccifer 2.0 is linked to Russia. Emails stolen from the chairman of Hillary Clinton’s presidential campaign were later released by the website Wikileaks.

U.S. intelligence agencies later concluded that the Russian government directed the DNC hack in an attempt to influence the outcome of the presidential election.

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Stone told CBS News earlier this month that the FBI -- investigating whether there were improper contacts between the Trump campaign and Russians -- will “get my grocery lists, they may get the emails between my wife and I, but here’s what they won’t get -- any contact with the Russians.”

On Sunday, Stone said in a statement that when he had his “brief exchange” with Guccifer 2.0. on August 16, he was unaware of any allegations that Guccifer 2.0 was or is a Russian agent.

He also said that because August 16 was after the DNC email hack and release, the timeline proves he wasn’t involved in the hack and release of the emails.

“Therefore my previous statements to CBS that I had contact with NO Russians is accurate with the possible exception of an innocent exchange ... before I was aware of these allegations that he may be a Russian asset,” Stone said in a statement.

Stone is a friend of Mr. Trump and was an informal adviser to his campaign.

His acknowledgement of contact with Guccifer, however brief, could pose fresh problems for Mr. Trump, whose administration has been unable to surmount suspicion over campaign-season contacts with Russia. The FBI is investigating, as are the House and Senate intelligence committees.

Mr. Trump has denied knowing that any staff had communicated with Russia during the campaign. The president recently fired Michael Flynn from his job as national security adviser after it came to light that Flynn hadn’t been direct about his own contacts with Russia’s ambassador to the U.S.

CBS News correspondent Jeff Pegues reported earlier this month that Stone had denied any connection to Russia and refuted allegations he knew Wikileaks was going to publish the stolen emails of Hillary Clinton campaign chairman John Podesta.

But in August, Stone tweeted “it will soon [be] Podesta’s time in the barrell.” Nearly two months later, Wikileaks began publishing new Podesta emails every day.