(Reuters) -UnitedHealth Group ( UNH ) CEO Andrew Witty called the U.S. healthcare system flawed and said the company, along with employers and governments, needs to work on the way it explains insurance coverage decisions.

In a New York Times opinion piece on Friday, Witty mourned the killing of Brian Thompson, the CEO of UnitedHealth's ( UNH ) health insurance unit, last week.

In his first public statement since the killing, Witty also said the company was "struggling to make sense of this unconscionable act and the vitriol that has been directed at our colleagues who have been barraged by threats."

Luigi Mangione has been charged with murder for the killing of Thompson in a brazen shooting on Dec. 4 outside a Manhattan hotel before an industry conference, setting off a five-day manhunt for the masked assailant.

The killing has ignited an outpouring of anger from Americans struggling to receive and pay for medical care.

(Reporting by Manas Mishra in Bengaluru; Editing by Anil D'Silva)