No clear winner has emerged at the Republican Iowa caucus so far.

Results available for 538 out of 1,774 precincts show that three Republican presidential candidates - Mitt Romney, Ron Paul and Rick Santorum - have each won 23 per cent of the votes in the polling held on Tuesday.

Other candidates Newt Gingrich (13 per cent), Rick Perry (10 per cent) and Michele Bachmann (six per cent) have moved to the second spot.

In the coming weeks, a series of caucuses and primary elections will be held across the 50 states before a presidential candidate to contest against Democratic candidate President Barack Obama in November this year is finalised.

The party nominee will finally be announced at the Republican National Convention to be held in August .

Some 120,000 voters exercised their franchise across the state. Before the polling, voters were allowed to speak on behalf of their candidates.

The next primary election will be held in New Hampshire on January 10. Mitt Romney has a big lead there, according to surveys.

Primary elections will be held in South Carolina and Florida on January 21 and 31.

According to a survey, the economy and the budget deficit are the main campaign issues rather than abortion or healthcare, reports