Joe Biden admits Iowa was a 'gut punch' and goes on the attack against Pete Buttigieg and Bernie Sanders

Joe Biden has acknowledged his campaign's weak performance in Iowa, describing the night as a "gut punch" in a speech to supporters as state officials slowly released results from the first-in-the-nation caucus throughout the week.

The former vice president, who was in fourth place according to the latest results from Iowa, spoke out about the many issues plaguing the state’s caucus night while looking ahead to New Hampshire and other key early-voting states on Wednesday.

“I’m not going to sugarcoat it,” the 2020 hopeful told voters. “We took a gut punch in Iowa.”

“The whole process took a gut punch,” he added. “But look: this isn’t the first time in my life I’ve been knocked down.”

Mr Biden’s comments came as Pete Buttigieg appeared to lead the crowded field of Democratic presidential candidates in Iowa with 75 per cent of precincts reporting, as Bernie Sanders trailed closely behind him in second place. Elizabeth Warren also picked up a significant delegate-count from the state as the apparent third-place winner of the night.

While the Democratic primaries have largely gone by without direct attacks between candidates vying for a shot at unseating Donald Trump, Mr Biden appeared to then take the gloves off while addressing several of those who seemingly bested him in Iowa.

“If [Bernie] Sanders is the nominee for the party, every Democrat in America up and down the ballot, in blue states, red states, purple states, in easy districts and competitive ones, every Democrat will have to carry the label Senator Sanders has chosen for himself” Mr Biden said, referring to the “Democratic Socialist” label Mr Sanders and many of his supporters use to describe the Vermont senator’s platform.

“He calls him — and I don't criticise him — he calls himself a democratic socialist,” the former vice president continued. “Well, we're already seeing what Donald Trump is gonna do with that."

He also derided past statements made by Mr Buttigieg, the former mayor of South Bend, Indiana, who would become the first openly gay president if elected in 2020.

“Mayor Pete likes to call me part of the old failed Washington,” Mr Biden wrote in a tweet. “Was it a failure when I helped pass Obamacare, the Paris Agreement, the Violence Against Women Act, or the assault weapons ban?"

He added: “I have a stronger record of passing big, progressive legislation than anyone running."

Mr Sanders appeared likely to have another strong showing in New Hampshire, potentially spelling trouble for the former vice president’s fundraising efforts as he continues seeking the Democratic nomination.

Still, Mr Biden said he was staying in the race and pushing forward with his campaign.

“There are an awful lot of folks out there who wrote off this campaign ... They’ve been trying to do that from the moment I entered the race,” he said. “Well, I’ve got news for them. I’m not going anywhere,” he said.