Roger Stone, a confidant of President Trump, denied coordinating with the Russian government or Julian Assange and WikiLeaks to aid Trump's campaign.

Stone said on CNN Thursday he's ready to testify under oath whenever he's called in front of Congress about his activities during the presidential campaign. Stone, an often-controversial figure, believes he's been under surveillance by the federal government and believes investigators know he has nothing to hide.

"They can call me a dirty trickster but there's one trick that's not in my bag: treason," he said. "And Donald Trump didn't need help from the Russians to beat Hillary Clinton."

Stone is under scrutiny because he is seen as a possible link between the Trump campaign and WikiLeaks, which released thousands of emails hacked from the Democratic National Committee and Clinton's campaign chairman, John Podesta.

He denied having information about WikiLeaks' pending release of Podesta's emails in a tweet from late in the campaign, when he predicted information would be coming out that could end Clinton's campaign.

Stone said he was merely predicting that Podesta's business activities would become controversial and he had seen opposition research that could hurt Clinton's campaign.

"I had no advance knowledge that WikiLeaks would hack his email," he said. "I never said that, I never predicted it."