US President-elect Donald Trump has appointed Jones Day partner Donald McGahn as his White House counsel.

McGahn served as general counsel to Trump's campaign and has continued in that role for the transition since the election.

Trump praised McGahn's "brilliant legal mind, excellent character and a deep understanding of constitutional law".

McGahn said in a statement that he was "honoured" to continue advising Trump.

"President-elect Trump is a bold leader committed to draining the swamp in Washington and restoring economic prosperity and security. I look forward to serving the American public in this role," he said.

McGahn, who is based in Washington, has a background in election law. He is a former commissioner and chairman of the Federal Election Commission; McGahn served on the commission from 2008 to 2013 and was credited as a major force in efforts to loosen regulations on campaign spending.

He also spent nearly a decade as general counsel for the National Republican Congressional Committee.

The announcement included statements of approval from former White House counsel Boyden Gray, now at Boyden Gray & Associates, and former US attorney general Edwin Meese.

"The counsel to the president needs solid Washington experience, but also a serious prior relationship with the president that allows for candour, and a practical understanding of how government agencies function," Gray said. "Donald McGahn possesses all these attributes and can serve President-elect Trump well."

Representing Trump during the campaign proved lucrative for Jones Day – according to a report by the Daily Beast in early October, the campaign by then had spent $2.5m on legal services.

Jones Day has other ties to the nascent Trump administration. Partner Gregory Katsas and associate James Burnham are on the team overseeing the US Department of Justice transition.