Prominent investigative journalist Carl Bernstein says President Donald Trumps administration is in chaos less than two weeks after he took office.

"It’s apparent to all but his most serious defenders and those who are his greatest advocates," Bernstein said on CNN Monday night.

"Republicans on Capitol Hill who I'm talking to who are doubting his abilities," Bernstein said, "doubting even his stability under pressure. This is an extraordinary series of events."

Bernstein famously reported on the Watergate scandal during Richard Nixon's presidency in the 1970s, which eventually led to Nixon's resignation.

Trump on Monday night fired acting US Attorney General Sally Yates over her objections to his executive order on immigrants and refugees, after 72 hours of dissent from Republicans and Democrats following Trump's signing of the order last week.

Bernstein said that, while Trump was "within his rights" to dismiss Yates, "it was not wise that he did."

Hundreds of thousands of people have flooded the streets in the US and abroad protesting Trump's executive order, dubbed a "Muslim ban" by prominent critics because the order specifically targets immigrants and refugees from seven majority-Muslim nations.

Bernstein continued:

"[Trump] has obstructed the most basic of American principles of what we stand for as a country in terms of immigration; a nation of immigrants. These are authoritarian pronouncements that he has been making for days now, and it's starting to haunt him."

Aside from the immigration executive order, Trump in the first 10 days of his presidency has rhetorically rumbled with lawmakers, heads of state, and the press — and it's all happening under the specter of Trump's historically low 43% approval rating.