Donald Trump has mocked Michael Bloomberg after the billionaire was caught licking each of his fingers before reaching for a pitcher during a campaign event.

The president shared the video on Twitter, saying: "Mini Mike, don't lick your dirty fingers. Both unsanitary and dangerous to others and yourself!"

Bloomberg is seen in the video tearing off a piece of pizza, eating it and then placing the remaining part of the slice back in the box before reaching for the coffee pitcher.

Former New York mayor Bloomberg has traded insults and flimsy insults with the president on social media after Mr Bloomberg entered the race, powered by countless millions of dollars in advertising with the sole directive of booting the president from office in November.

The president's latest message arrived on Super Tuesday as results began to trickle in after polls closed in 14 states across the US.

Bloomberg ultimately won the only territory he didn't visit.

After spending more than half a billion dollars on his campaign, he was predicted to win the South Pacific territory of American Samoa, according to the American Samoa Democratic Committee.

Meanwhile, he is set to finish below delegate eligibility in Virginia, where he first held a campaign event.

He wrote on Twitter: "Thanks for your support, American Samoa! Together, we'll defeat Donald Trump and rebuild America."

His win there would give him a total of five delegates.