CNN apologises after producer jokes about Donald Trump's plane crashing

US' CNN television channel has apologised to Donald Trump after one of its producers was caught on a hot mic making a joke about the President-elect's plane crashing.

"An unfortunate and inappropriate remark was made by one of our producers off camera yesterday," a CNN spokesperson told Business Insider in a statement.

"We have apologised to the Trump transition team, and the producer has been disciplined," the spokesperson said.

As correspondent Suzanne Malveaux prepared for a live shot at Carrier's Indianapolis plant on Thursday, a producer was heard discussing various hand signals with her.

"That means his plane's crashed - just kidding," the producer said, prompting a stunned face from Malveaux.

Trump had strongly criticised CNN during the presidential campaign.

During the campaign he referred to the outlet as the "Clinton News Network" and, according to reports, criticised its president during a recent closed door meeting with top television executives.