US Strategic Command, which oversees America's nuclear arsenal, has apologised for a tweet that said it was ready to "drop something much, much bigger" than New York's Times Square ball.

The message, posted on New Year's Eve, was accompanied by a video showing a B-2 bomber dropping weapons.

Strategic Command later deleted the tweet, saying it was "in poor taste", and replaced it with an apology.

The incident sparked outrage online.

The previous tweet read:

"#TimesSquare tradition rings in the #NewYear by dropping the big ball...if ever needed, we are #ready to drop something much, much bigger."

It was posted online hours before the annual "ball drop" on top of One Times Square, a New York skyscraper, which marks the start of the new year. The tradition began in 1907, and sees a brightly-lit ball on a special flagpole descend 43m (141ft) in the 60 seconds before midnight, coming to rest as the new year begins.

Critics were quick to condemn Strategic Command's take on the event.

Former head of the US Office of Government Ethics, Walter M Shaub Jr, tweeted: "What kind of maniacs are running this country?"

Joe Cirincione, author of 'Nuclear Nightmares, Securing the World before it is too late', said: "At first, I did not believe this could be real. But it is. It is an industry ad doubling as a sick, bragging joke by our Strategic Command. Disgraceful."

US Strategic Command is one of 10 unified commands in the US Department of Defense. It is based at Offutt Air Force Base in Nebraska. The command slogan is "Peace is Our Profession", which was also used in hashtag form in the controversial tweet.