Senator Cory BookerImage copyright

US Democratic presidential candidate Cory Booker has announced he is ending his campaign after disappointing poll numbers.

The New Jersey senator had failed to qualify for the Democratic debate on Tuesday in Iowa.

Mr Booker had been touted as a rising star of his party, but was unable to garner enough support in a crowded field.

There are now 12 remaining Democrats in the race for the White House.

“Today I’m suspending my campaign for president with the same spirit with which it began,” Mr Booker said in a video announcing the end of his campaign.

“It is my faith in us, my faith in us together as a nation. We share a common pain and common problems that can only be solved with a common purpose and common cause.”

Mr Booker polled an average of 2% nationally, according to RealClearPolitics data, while front-runners Joe Biden and Bernie Sanders have been polling at 29% and 20% on average respectively.

Fellow Democratic contender Marianne Williamson quit the race at the weekend, while Julian Castro dropped out of the race earlier this month.