US media tycoon Mike Bloomberg on Wednesday announced to suspended his campaign for Democratic presidential nomination, ending the most expensive primary campaign team in the history of the country. 

The billionaire businessman and former New York City mayor endorsed former Vice President Joe Biden for the Democratic nomination as he announced the end of his campaign. 

Bloomberg had spent millions of his own money in advertisements as he launched the bid for Democratic nomination. However, he failed to win a single state that went to polls including so far, including the 14 states that voted on Super Tuesday.

Announcing the end of his presidential bid on Twitter, Bloomberg said, "Three months ago, I entered the race to defeat Donald Trump. Today, I'm leaving for the same reason. Defeating Trump starts with uniting behind the candidate with the best shot to do it. It's clear that is my friend and a great American, @JoeBiden."

"I'm immensely proud of the campaign we ran. I'm deeply grateful to all the Americans who voted for me, and to our dedicated staff and volunteers. I want you to stay engaged, active, and committed to our issues. I will be right there with you. And together, we will get it done," he added. 

With the exit of Bloomberg from the primaries, there are only four contenders left in the race. While Tulsi Gabbard has failed to make any impact so far, Elizabeth Warren is still in the race dominated by two frontrunners Joe Biden and Bernie Sanders. 

Whoever wins the Democratic nomination will battle it out with President Donald Trump in the presidential election coming November.