Former United States President Donald Trump has decisively won the Iowa caucuses, cementing his Republican frontrunner status as he bids to retake the White House in 2024.

Trump handily beat former US Ambassador to the United Nations Nikki Haley and Florida Governor Ron DeSantis in a widely-expected result on Monday, taking him a step closer to securing a third consecutive nomination for the presidency.

Trump won at least 20 of 40 delegates, with DeSantis taking eight and Haley receiving seven, provisional tallies showed, with US media outlets calling the state-wide contest about 30 minutes after the start of voting.

Biotech startup founder Vivek Ramaswamy, who won two delegates, announced as the results came in that he was quitting the race and would endorse Trump.

Trump’s commanding victory points to his continuing dominance over the Republican Party, even as he faces mounting legal woes including four criminal indictments.

On Tuesday, Trump is expected to appear in court in New York as a jury considers whether he should pay further damages to a writer who won a $5m jury award against him for sexual assault and defamation.

Trump’s legal challenges have done little to dampen his support among Republicans, many of whom view the cases against him as politically motivated.

Iowa has a mixed record of predicting the eventual Republican nominee – George W Bush was the last GOP presidential candidate to win the state in 2000.