US President Donald Trump has been growing increasingly frustrated with the challenges of running the White House, according to his aides and allies.

The new president’s mood has switched from surprise to anger as he has faced the predictable realities that the US government cannot be run like his business empire, Politico reported Friday, quoting nearly two dozen people who have spent time with Trump in the three weeks since his inauguration.

The transition from overseeing a family business to running the country has been tough on Trump, those close to the president said, most of whom requested anonymity to describe the inner workings of the White House.

They said Trump has become particularity frustrated with the massive federal bureaucracy, including congressional delays over his cabinet nominations and legal battles holding up his controversial executive orders.

During his presidential election campaign, the billionaire businessman sold himself to voters as being uniquely qualified to fix the nation’s ailments.

The people interviewed describe the White House as a tense workplace where job duties are unclear, morale among some staff is low, internal conflict is extensive and exhaustion is running high.

Some staffers are reportedly worried about coming into conflict with Jared Kushner, Trump’s son-in-law who is among his most trusted advisers. The staffers say they are unclear about Kushner’s role, describing his portfolio as amorphous. “No one quite knows what it is,” said one aide. “It’s confusing.”

Kushner played a key role in blocking New Jersey Governor and former Republican presidential candidate Chris Christie from getting a senior job in the Trump administration.

Christie, who was the US Attorney for the District of New Jersey before becoming governor, was involved in the prosecution of Kushner’s father, Charles Kushner, who was sentenced to two years in prison in 2005 for tax evasion, witness tampering and making illegal campaign donations.