President Trump's former campaign manager charged that his staff is struggling to prepare the president.

"The staff has probably not prepared him as well as they could have or should have," Corey Lewandowski said in an interview with David Axelrod's "The Ax Files" podcast, published Monday.

Lewandowski noted that no one in Trump's senior staff "ever worked inside the government." He cited the White House's struggle to successfully roll out Trump's immigration executive order as one of those issues.

Despite the criticism, Lewandowski praised Trump for moving quickly on his campaign promises.

"I think you have a president who wants to move very quickly, who has a grand vision of what he wants to accomplish and is leaving the details to the staff to implement," he said.

In addition to the controversy around the immigration order, Trump's national security adviser Mike Flynn had to resign, and his pick for labor secretary Andrew Puzder had to withdraw his nomination.