FILE - Environmental Protection Agency Administrator Scott Pruitt appears before a Senate Appropriations subcommittee on the Interior, Environment, and Related Agencies on budget on Capitol Hill in Washington, May 16, 2018. Newly filed disclosure rep
FILE - Environmental Protection Agency Administrator Scott Pruitt appears before a Senate Appropriations subcommittee on the Interior, Environment, and Related Agencies on budget on Capitol Hill in Washington, May 16, 2018. Newly filed disclosure rep

Embattled Environmental Protection Agency chief Scott Pruitt has resigned after fighting numerous scandals and alleged ethics violations.

"The unrelenting attacks on me personally, my family, are unprecedented and have taken a sizable toll on all of us," Pruitt wrote in his resignation letter to President Donald Trump on Thursday.

He wrote that it is "extremely difficult" to step down, but did not directly mention or apologize for any of the scandals that have overshadowed the EPA.

Trump told reporters on Air Force One there was no "final straw" that led to Pruitt's resignation.

"Scott is a terrific guy. He came to me and said, 'I have such great confidence in the administration, I don't want to be a distraction.' He'll go and do great things and have a wonderful life, I hope."

Trump declined to mention the controversy surrounding someone who had been one of his most loyal Cabinet members.

As recently as a few weeks ago, Trump continued to defend Pruitt and complained about the "vicious" attacks from the press.

But during a brief meeting with reporters outside the White House, Trump said Pruitt is not "blameless." Trump did not comment when a reporter asked him if he was "tired" of Pruitt.

Federal officials are looking into a number of questions surrounding Pruitt, including taxpayer-funded first-class airline travel and ordering a $43,000 soundproof booth for his office. Pruitt is also said to have rented a Washington apartment from a lobbyist for just $50 a day when such places cost thousands of dollars a month.

FILE - Andrew Wheeler, currently the No. 2 officia
FILE - Andrew Wheeler, currently the No. 2 official at EPA, will take over as acting administrator on July 9, 2018.

EPA staffers say Pruitt used them for such chores as booking personal travel, helping his wife find a job, picking up his laundry and obtaining a used mattress from a Trump hotel.

But environmentalists say none of these scandals are as important as Pruitt's zeal for deregulation by an agency that has a mission to protect the air and water.

They accused Pruitt of doing the bidding of the energy and fossil fuel industries by rolling back a number of pollution rules put in place by the Obama administration. Pruitt also banned the words "climate change" from the EPA website.

Pruitt had cited a number of these rules as examples of government overreach, with standards that are too high and unrealistic, believing the environment can be protected while industry and jobs are allowed to thrive.

Trump says Pruitt's deputy, Andrew Wheeler, will take over as acting EPA chief.

Pruitt is a former Oklahoma attorney general and was EPA director for 16 months.