Lewis "Scooter" Libby, U.S. Vice President Dick Cheney's former chief of staff, leaves federal court in Washington in 2006. President Trump is considering pardoning Libby. (JIM YOUNG/REUTERS)

President Trump is expected to pardon Lewis “Scooter” Libby, according to a senior administration official, giving an olive branch to a George W. Bush administration staffer that the former president declined to grant.

It is unclear why Trump is making the move, but the pardon has been under consideration for several months, two people familiar with the president’s thinking said. Trump has often privately expressed a willingness to pardon Libby, who was convicted of obstruction of justice and perjury in the disclosure of a CIA agent’s name.

Trump could always change his mind, the senior administration official said. The timing of the pardon is unclear.

The news was first reported by ABC News.

Libby was the chief of staff to Vice President Richard B. Cheney and a controversial figure in the Bush administration.

Bush, whom Trump often derides in caustic terms, could not be persuaded to pardon Libby. He was lobbied aggressively by Cheney, and his refusal was said to have caused a strain in the relationship between the two men.

Trump, who often rails against disclosures to the news media but was a longtime anonymous source himself, appears to have chosen to forgive Libby for his role in the disclosure of CIA agent Valerie Plame’s identification.

Libby was convicted of making false statements, perjury and obstruction of justice in the 2007 investigation of Plame, a former covert CIA agent and the wife of former ambassador Joseph C. Wilson IV.

Libby was sentenced to 30 months in prison and fined $250,000, but his sentence was commuted by Bush. Although spared jail time, Libby was not pardoned.

The chief federal prosecutor in Libby’s case was Patrick Fitzgerald, then the U.S. attorney from the Northern District of Illinois. Fitzgerald is a longtime friend and colleague of James B. Comey, the fired FBI director whose new memoir paints a scathing portrait of Trump’s character and conduct in office.

Trump has rarely used his presidential power to pardon, but last August granted clemency to Joe Arpaio, a controversial Arizona sheriff who had been a longtime Trump ally and campaign-trail companion.

Arpaio was found in contempt of court for defying a federal judge’s order to stop detaining people simply because he suspected them of being undocumented immigrants. In addition to racial profiling, Arpaio was long criticized for what many in the community decried as inhumane prisons in Maricopa County, which includes Phoenix.

Trump and Arpaio’s political alliance dates to the “birther” movement earlier this decade. Both men were outspoken leaders of the campaign to undermine President Barack Obama by spreading the lie that he was born outside the United States when, in fact, he was born in Hawaii.

John Dowd, a former Trump lawyer, floated pardons to former campaign manager Paul Manafort and former national security adviser Michael Flynn, The Washington Post has reported. Manafort has since been charged with more than a dozen offenses, while Flynn has pleaded guilty to lying to the FBI.