NORFOLK, Va — President Trump on Saturday asserted the “complete power to pardon” relatives, aides and possibly even himself in response to investigations into Russia’s meddling in last year’s election, as he came to the defense of Attorney General Jeff Sessions just days after expressing regret about appointing him.

Mr. Trump suggested in a series of early morning messages on Twitter that he had no need to use the pardon power at this point but left the option open. Presidents have the authority to pardon others for federal crimes, but legal scholars debate whether a president can pardon himself. Mr. Trump’s use of the word “complete” seemed to suggest he did not see a limit to that authority.

“While all agree the U.S. President has the complete power to pardon, why think of that when only crime so far is LEAKS against us,” he wrote on Twitter. “FAKE NEWS.”

The Washington Post reported in recent days that the president and his advisers had discussed pardons as a special counsel intensifies an investigation into whether associates of Mr. Trump and his campaign conspired with Russia to intervene in the 2016 presidential campaign.