Washington (CNN) Former Vice President Joe Biden said Friday that "decency" in the White House had hit "rock bottom" following a White House aide's joke about Sen. John McCain's health.

"People have wondered when decency would hit rock bottom with this administration. It happened yesterday," Biden said in a striking statement.

The statement was in response to White House aide Kelly Sadler's comments following the Arizona Republican's opposition to President Donald Trump's pick for CIA director by saying Thursday morning that "he's dying anyway," a White House official told CNN. Asked about Sadler's comment, a White House official said, "We respect Senator McCain's service to our nation, and he and his family are in our prayers during this difficult time."

White House press secretary Sarah Sanders declined to comment later Friday on Sadler's remark, saying, "I'm not going to comment on an internal staff meeting."

McCain announced last year that he had been diagnosed with brain cancer and has been spending time with family and loved ones while he receives treatment in Arizona.