Pruitt's round-the-clock security has cost taxpayers almost $3 million

US President Donald Trump listens to Environmental Protection Agency Administrator Scott Pruitt speak after announcing the US will withdraw from the Paris accord in the Rose Garden of the White House

"While security spending was somewhat more than his predecessor, Scott Pruitt has received death threats because of his bold actions at EPA", Pres. Trump said in a Twitter message late Saturday.

EPA spokesman Jahan Wilcox said last week there had been an "unprecedented" amount of death threats against Pruitt and his family.

Since coming to the agency, Pruitt has demanded more security than any of his predecessors, requesting a round-the-clock security detail that has cost taxpayers almost $3 million.

Pruitt suggested the lobbyist whose wife rented him the $50 a night condo - well below market rates - had been a friend for years, but the lobbyist suggested they were only casual acquaintances.

While some White House aides are increasingly fed up with Pruitt and chief of staff John Kelly has advocated firing him, Trump remains less certain.

Mr. Pruitt had complained that his 19 full time body guards and 19 armored vehicles dedicated exclusively to protect him in his risky job were inadequate and insufficient for the threat vectors in the Oklahoma-Washington DC environment. Mario Caraballo, a military veteran who served as deputy associate administrator at the EPA's Office of Homeland Security, was placed on leave.

Pruitt has been heavily criticized over the last few weeks due to excessive spending and possible ethics violations.

The Hart's were also donors and fundraisers for Pruitt while he was a politician in Oklahoma. When asked about the threats to Pruitt's safety on Monday, White House press secretary Sarah Huckabee Sanders said she couldn't cite any specifics or police reports but that the White House was continuing to review the administrator's conduct.

After news of the raises - of $56,765 for Greenwalt and $28,130 for Hupp - became public, Pruitt gave an interview with Fox News where he said he had no knowledge of the salary increases until reports came out.

Shortly after arriving in Washington, Pruitt demoted the career staff member heading his security detail and replaced him with EPA Senior Special Agent Pasquale "Nino" Perrotta, a former Secret Service agent who operates a private security company. His stature among deep red members of the Republican Party and skills as an environmental lawyer also mean that it would be very hard to push a replacement of equal talent through the Senate in the next six months.

"This is kind of an unprecedented situation as far as I know", Jennifer Kaplan, a spokeswoman for the EPA Office of Inspector General, told BuzzFeed News, referring to the unusual way the request landed on the IG's desk after originating with the Office of Government Ethics and then getting bounced off EPA's ethics office.

Rep. Carlos Curbelo, R-Fla., co-chairman of the bipartisan Climate Solutions Caucus, has urged Trump to fire Pruitt. Several of the staffers raised concerns about Pruitt flying first class, a habit the administrator indulged in more often after one of them was sidelined.

Though Pruitt has shown no intention of relinquishing his post, and President Trump has continued to voice his support, the ongoing scrutiny has influenced the administrator's travel schedule.