WASHINGTON >> The acting head of the Drug Enforcement Administration will resign at the end of the week, according to law enforcement officials, who said he had become convinced that President Donald Trump has little respect for the law.

The official, Chuck Rosenberg, who twice served as chief of staff to former FBI Director James B. Comey and remains a close confidant, had grown disillusioned with Trump. The president fired Comey in May, and then in July told law enforcement officers “please don’t be too nice” when handling crime suspects.

Rosenberg forcefully rejected Trump’s comment, sending an email to all DEA employees to tell them that they should not mistreat suspects.

“We must earn and keep the public trust and continue to hold ourselves to the very highest standards,” Rosenberg wrote in the internal email. “Ours is an honorable profession and, so, we will always act honorably.”

Rosenberg, who was appointed by President Barack Obama in 2015, is a career prosecutor. Under President George W. Bush, he served as the U.S. attorney in both southern Texas and eastern Virginia.

In late July, Rosenberg, told the deputy attorney general, Rod J. Rosenstein, that he did not want to be considered as the permanent administrator of the DEA. Rosenstein then asked whether Rosenberg wanted any other job in the Justice Department, and Rosenberg said he did not.