Voters in the US state of Iowa will start the 2024 Republican presidential nomination process when they head to caucus meetings on Monday.

The Iowa caucuses begin at 7 p.m. local time. Participants will listen to last-minute pitches by representatives for candidates, before casting ballots.

A series of nationwide polls showed former President Donald Trump with support from more than 60 percent of Republicans on average, followed by former UN Ambassador Nikki Haley and Florida Governor Ron DeSantis.

The Iowa caucuses will be a test of Trump's perceived lead in the race. The results in Iowa -- the state that votes first for a presidential nominee -- are said to have huge implications for the nomination processes elsewhere.

Attention is also on the severe cold weather in the state. Analysts say the frigid conditions could reduce voter turnout.

The caucuses come amid Trump's indictment in four separate cases. There have also been legal attempts across the US to strip the former president of his eligibility to be nominated.

Vote-counting begins immediately after the polling ends.