White House press secretary Sarah Huckabee Sanders said Wednesday that President Trump’s chief of staff is “disgusted” that the death of his son has become politicized — even though it was Trump who thrust the Marine's death into the political glare.

In an interview with Fox News radio this week, Trump cited John Kelly, his chief of staff, as he attempted to bolster his false claim a day earlier that President Barack Obama had never called families of fallen U.S. service members.

“You could ask General Kelly, did he get a call from Obama?” Trump said in the interview, referring to the death of Kelly’s son, 1st Lt. Robert M. Kelly, who died in southern Afghanistan in 2010 when he stepped on a land mine.

During Wednesday’s White House briefing, Sanders faced questions about how long it took Trump to reach out to the families of four Special Forces soldiers killed two weeks ago in Niger, where they had been dispatched to patrol with troops from that country.

During the briefing, Sanders was asked if Trump had given his chief of staff advance warning that he “would be raising the issue of his son's memory” earlier in the week and whether Kelly was comfortable that it had become part of the conversation.

“I think General Kelly is disgusted by the way that this has been politicized, and that the focus has become on the process and not the fact that American lives were lost,” Sanders said. “I think he's disgusted and frustrated by that. If he has any anger, it's toward that.”

When it was pointed out that Trump himself had  injected the death into the debate, Sanders said, “He was responding to a question and stating a fact.”

Since the loss of his son seven years ago, Kelly, a retired U.S. Marine Corps general, has gone out of his way to keep his son’s death from the political debate.

Two White House officials said earlier this week that they were caught off guard by Trump’s comments on Kelly’s son. One said Kelly might have mentioned some details surrounding his son’s death to the president in private and that the president then repeated them in public, a frequent occurrence with Trump.

Kelly, who became the highest-ranking military official to lose a child in Iraq or Afghanistan, watched both his sons follow him into the Marine Corps. When Robert died, Kelly and his sons had participated in 11 combat tours in Iraq and Afghanistan combined.

Ashley Parker contributed to this story.