Sanders: Aide's McCain Comment Shouldn't Have Been Leaked

White House Press Secretary Sarah Huckabee Sanders told staffers Friday that an aide's recent comment about Sen. John McCain was inappropriate but shouldn't have been leaked to the media.

Sanders told communications' staffers in a private meeting that it was inappropriate for aide Kelly Sadler to dismiss McCain's opinion during a recent closed-door meeting because, Sadler said, "he's dying anyway."

Sanders said the leak was selfish and distracted from the president's agenda and "everything we're trying to accomplish for the American people," according to a person familiar with the meeting who spoke on condition of anonymity to describe the private meeting. She noted that it garnered attention following the president's welcoming home of three Americans detained in North Korea and an upcoming summit with Kim Jong Un in Singapore.

During the meeting, White House director of strategic communications Mercedes Schlapp defended Sadler, saying the private comments shouldn't have been leaked to the media, the person said.

Sanders declined to condemn Sadler's comments during a White House briefing on Friday, saying she wouldn't "validate a leak out of an internal staff meeting."

McCain, the 81-year-old Arizona GOP senator, was diagnosed in July with glioblastoma, an aggressive brain cancer. He left Washington in December and underwent surgery last month for an infection.

Sadler is a special assistant to the president. She has declined to respond to requests for comment on her McCain remark.