US presidential hopeful Bernie Sanders has attacked his Democrat and Republican rivals ahead of the Iowa caucus on 1 February. The candidate hit out at Hillary Clinton over funding for her campaign while speaking in Des Moines on 31 January.

He said: "My opponent yesterday announced that she had received some $45m for her super-PAC [political action committees]. We announced that we received zero dollars for our super-PAC. But this is what we also announced. We announced that we have received throughout this campaign and this is so unbelievable, never in a million years would I have thought this possible.

"We have received up to now 3.2 million individual contributions. And that is more contributions than any candidate up until this point in a campaign in the history of the United States of America".

US election 2016: Guide to the Democrat candidatesIBTimes UK

Sanders added that the average contribution to his campaign was around $27 (£19). The liberal candidate also spoke out against Republican front runner Donald Trump in the speech, accusing the business mogul of trying to divide America.

He said: "What this campaign is about, of course I'm here to try and win tomorrow night, to try to win the democratic nomination, try to win the general election. But more important and part of the process are millions of people coming together, black and white and Latino, gay and straight, male and female, people born in this country, people who have immigrated into this country. We will not allow Donald Trumps and the other people to divide us up. We will stand together."

US election 2016: Guide to the Republican candidatesIBTimes UK

The Iowa vote for both the Republican and Democrat presidential nominations take place on 1 February. It is the first state to vote in the races, and often seen as a key sign of how the nominations are going to pan out.