At a campaign-style speech at the Iowa state fairgrounds, Trump said he is working with the homeland security department to help farmers who depend on migrant labourers for their seasonal needs. He said he will also work with the hotel industry on the issue.

Trump has been pursuing a hard-line policy on migration and his US homeland security secretary Kristi Noem has been leading an effort to deport people who crossed into the US illegally.

This has led to some complaints from farmers that their crops are at risk due to a depleted work force.

“If a farmer is willing to vouch for these people in some way, Kristi, I think we’re going to have to just say that’s going to be good, right?”

“We don’t want to do it where we take all of the workers off the farms,” he added, speaking in a Midwestern state where farming is a dominant industry.