Image copyright Getty Images Image caption "May I remind you my husband has a family", Mrs McCain tweeted

The daughter of US Senator John McCain has hit back at a White House aide who reportedly joked his vote "doesn't matter" because "he's dying anyway".

The remark from Special Assistant to the President Kelly Sadler came during a meeting to discuss the nominee for CIA director, according to US media.

Mr McCain was tortured during the war in Vietnam, and opposes the CIA nominee due to her waterboarding record.

Meghan McCain suggested that the aide should lose her White House job.

"Kelly, news flash, We're all dying…It's not how you die, it's how you live," she said on Friday's episode of the TV programme The View, referring to the White House aide.

"The thing that surprised me most is, I don't understand what kind of environment you're working in where that would be acceptable, and then you can come to work the next day and still have a job," the co-host continued.

On Thursday, the Arizona senator's wife took to Twitter to call out Ms Sadler's comment, which US media reported was a failed attempt at a joke.

"May I remind you my husband has a family," Cindy McCain wrote.

She tweeted at Ms Sadler, adding that the former Republican presidential candidate has seven children and five grandchildren.

Mr McCain, 81, has been diagnosed with a rare form of brain cancer, and has been resting at his family retreat in Sedona, Arizona in recent weeks.

The comment was first reported in the Hill newspaper, which added that Ms Sadler had called the senator's daughter, Meghan McCain, to apologise.

The White House responded to the report in a statement and did not dispute that Ms Sadler made the comment at a meeting.

"We respect Senator McCain's service to our nation and he and his family are in our prayers during this difficult time," the statement said.

Image copyright Getty Images Image caption Ms McCain questioned why it was acceptable for the aide to keep her job after allegedly making the remark

Politics are personal

Analysis by Anthony Zurcher, BBC News, Washington

Donald Trump belittled John McCain's war record. A pro-Trump television analyst recently mocked his military heroism. A White House aide joked about his terminal illness.

Politics can get painfully personal - but these swipes are more than just schoolyard taunts. They underline the fact that Mr McCain and Mr Trump represent distinct views of where the Republican Party should be headed.

Mr McCain has spent his 35 years in politics pushing for an expansive, internationalist foreign policy. He has advocated for free trade deals, multilateralism and robust environmental regulation. His life's experience is a testament to service, sacrifice and the seriousness of public office.

Mr Trump, on the other hand, campaigned on a kind of nationalism - on trade, foreign policy and immigration - that stands in stark contrast to Mr McCain's vision. The president's personal history, as a high-flying real estate mogul and reality-show impresario, couldn't be more different either.

Mr McCain, in book excerpts and press statements, is making his final push for the heart and soul of the Republican Party. The Trump team is responding as it always has - punching hard, no holds barred. Although the combatants may pass from the scene, it's a fight that won't end anytime soon.

Earlier this week, Mr McCain - who was held captive for more than five years during the Vietnam War - called upon his colleagues in the Senate to reject CIA nominee Gina Haspel.

He said her "refusal to acknowledge torture's immorality is disqualifying".

Despite the senator's opposition, as well as opposition from many Democrats, Ms Haspel is expected to be confirmed by the full Senate next week.

Democratic Senator Tim Kaine tweeted his support for Mr McCain's decision, adding that he would also oppose her nomination.

Meanwhile, a Fox Business Network host has apologised for a remark his guest, a retired three-star general, made on his programme about Mr McCain's experience with torture.

Retired Air Force Lt Gen Thomas McInerney told host Charles Payne that Mr McCain was opposing Ms Haspel's nomination because torture "worked" on him when he was a prisoner of war.

"The fact is John McCain - it worked on John," he said on Thursday. "That's why they call him 'Songbird John.'"

Mr Payne tweeted that the comments were "very false and derogatory" and "should have been challenged".

US President Donald Trump has long been a critic of Mr McCain, and drew widespread condemnation from Republicans during his presidential campaign when he implied that the former Navy pilot was "not a war hero".

"He's a war hero because he was captured? I like people that weren't captured," Mr Trump said in 2015.

Excerpts from Mr McCain's forthcoming book, The Restless Wave, have been released to US media this week.

Media playback is unsupported on your device Media caption Watch McCain topple Trump's 'skinny repeal' healthcare bill

In the book, he describes receiving a phone call from President Barack Obama, thanking him for blocking a vote to repeal Mr Obama's signature healthcare law.

"I appreciated his call, but, as I said, my purpose hadn't been to preserve his signature accomplishment but to insist on a better alternative, and to give the Senate an opportunity to work together to find one.

"He hadn't called to lobby me before the vote, which I had appreciated," he writes.