Washington: On Friday, US President Donald Trump pardoned 11 individuals, including a former business associate of Washington lobbyist Jack Abramoff and nine people whom the White House said had assisted individuals in circumventing automobile emissions control systems.

The acts of clemency coincide with Trump's numerous pardons throughout his second administration, especially for prominent figures, allies and people who are considered to have political ties.

Among the ways the Republican's return to office has featured a wide use of executive power is his use of the president's broad authority to unilaterally commute sentences and grant pardons.

Trump earlier on Friday announced some of the pardons on social media without identifying any of the recipients by name.

"It is my Great Honor to have just signed Pardons for six people who were persecuted by the Biden Administration, and were in, or being sent to, prison, for fixing their car", Trump wrote on his Truth Social platform.

"I AM SETTING THEM ALL FREE, RIGHT NOW!" he said.

In a list provided on Friday evening by the White House, Trump pardoned 11 people, including nine who faced charges related to violations of the Clean Air Act by disabling emissions monitoring systems on vehicles or selling devices that enabled emissions systems to be bypassed.

The pardons come after Trump on Monday signed a memorandum directing the Environmental Protection Agency to allow Americans to modify their own vehicles as they see fit. As he signed the memorandum, Trump referred to a diesel mechanic he pardoned last year who had disabled emissions monitoring systems.

The memorandum also addressed aftermarket auto parts and would supersede the ability of the California Air Resources Board to evaluate parts that affect vehicle emissions.

The White House, while releasing the list of those pardoned, said Trump had "relieved consumers from these regulatory burdens".

Beyond the emissions-related pardons, Trump also issued a pardon for Adam Kidan, a former business partner of Abramoff.

Kidan pleaded guilty in 2005 to fraud and conspiracy related to the purchase of a fleet of gambling boats, and in 2006 he was sentenced to nearly six years in prison.

The case was part of a broader investigation into the early-2000s lobbying scandal involving Abramoff, Capitol Hill, the Interior Department and members of former US President George W. Bush's administration.

After leaving prison in 2009, Kidan began working at a staffing agency, later founded Chartwell Staffing Solutions and now serves as president of Empire Workforce Solutions, the White House said.

In March, the newspaper Newsday reported that Kidan was among the hosts of a fundraiser at Trump's Mar-a-Lago resort for a Long Island Republican congressional candidate.

A message sent to Kidan's business seeking comment was not immediately returned on Friday evening.

Trump also pardoned ranch owner Jack Harvard, citing his "upstanding record" after his conviction and praising him for allowing the US military and NATO troops to train on his land free of charge.

The White House did not immediately release additional details about Harvard, including the offence for which he had been convicted.