Donald Trump has offered hints at what his immigration policy will end up looking like during a campaign stop in Iowa.

The Republican nominee said he would remove 'bad guys' and undocumented immigrants with criminal records on 'day one'.

'I am going to begin swiftly removing criminal illegal immigrants from this country,' Trump told the mostly white crowd at the annual 'Roast and Ride' fundraiser in Iowa.

Donald Trump has offered hints at what his immigration policy will end up looking like during a campaign stop in Iowa

'I promise you, from the first day in office - the first thing I’m going to do, the first piece of paper that I’m going to sign is we’re gonna get rid of these people.

'Day one. Before the wall. Before anything. And our great law enforcement, they know who they are. We are gonna get rid of them day one. We start day one.

'These international gangs and cartels will be a thing of the past. Their reign of terror will be over.

'We are going to rid of the criminals, and it’s going to happen within one hour after I take office.

'We will move justly, but we will move fast. Believe me.'

Trump also said he is developing an 'exit-entry tracking system to ensure those who overstay their visas, that they're quickly removed.'

The Republican nominee said he would remove 'bad guys' and undocumented immigrants with criminal records on 'day one'

Trump was also was photographed hugging the brother of 21-year-old Sarah Root, who was killed in a car crash with an illegal immigrant who was drunk-driving in Omaha, Nebraska

Earlier in the rally, the Republican candidate was photographed hugging the brother of 21-year-old Sarah Root, who was killed in a car crash with an undocumented immigrant who was drunk-driving in Omaha, Nebraska.

Trump invited Scott Root and his parents, Michelle Root and Scott Bernhardt, onto the stage before putting his arms around him.

He also spoke to Ms Root as she appeared to be holding back tears.

Sarah Root died when Edwin Mejia, 19, was drunk and street racing another vehicle when his truck slammed into the back of her stopped SUV.

Michelle Root (right), the mother of Sarah Root who died in a DUI car accident, is with Republican nominee Donald Trump on stage in Iowa

Republican presidential candidate Donald Trump shares the stage with the family of Sarah Root at Joni's Roast and Ride at the Iowa State Fairgrounds in Des Moines

His blood alcohol content level at the time was .241, which is four times the legal limit to drive, and was driving on a suspended license and faces a motor vehicle homicide charge.

Trump also spoke about Root's death during his convention speech in July.

It comes after it emerged Trump is reportedly set to soften his extreme stance on immigration, by offering a pathway to citizenship to some of the 11 million undocumented immigrants and toning down talk of mass deportations, CBS News reported.

The reported softening of his policy has been criticized by a number of high-profile Republican figures, including former vice presidential candidate Sarah Palin.

'If Mr Trump were to go down a path of wishy-washy positions taken on things that the core foundation of his support has so appreciated, and that is respecting our Constitution and respecting law and order in America, then yeah, there would be massive disappointment,' Ms Palin told the Wall Street Journal.

Ann Coulter was also annoyed by Trump's switch, suggesting the candidate's message was being watered down.

'It sounds as if some campaign consultant has slipped into his campaign,' she told Fox News.

'I don’t think he should have been hiring Rubio’s speechwriter for his interview with you giving all these ridiculous talking points for amnesty.'

During Saturday's stop, Trump offered a hat-tip to Iowa's agriculture industry by renewing his commitment to continuing a requirement that all gasoline sold contain an ethanol-based additive, an issue important to corn growers.

Sarah Root died when Edwin Mejia, 19, was drunk and street racing another vehicle when his truck slammed into the back of her stopped SUV (pictured)

Trump also spoke about Root's (left) death during his convention speech in July. The young woman was killed when Edwin Mejia (right) crashed into her car while street racing

He also promised to cut taxes on family farms, which he called the 'backbone' of the country.

'Hillary Clinton wants to shut down family farms just like she wants to shut down the mines and the steelworkers,' he said in front of a wall of straw bales at the Iowa State Fairgrounds. 'She will do this not only through radical regulation, but also by raising taxes on family farms - and all businesses - to rates as high as nearly 50 per cent.'

Clinton's campaign website touts a plan to increase funding to support farmers and ranchers in local food markets and regional food systems, saying she'll create a 'focused safety net to help family farms get through challenging times.'

It also says she plans to target federal resources in commodity payment, crop insurance, and disaster assistance programs to support family operations.

Speaking to an overwhelmingly white crowd, he again pledged that as president he would help African-Americans living in cities with high crime and low employment.

A supporter wears a t-shirt in support of Republican presidential nominee Donald Trump at Senator Joni Ernst's Roast and Ride at the Iowa State Fairgrounds in Des Moines

'I promise you, from the first day in office - the first thing I’m going to do, the first piece of paper that I’m going to sign is we’re gonna get rid of these people,' Trump told the crowd

Republican presidential candidate Donald Trump greets the crowd after speaking at Joni's Roast and Ride at the Iowa State Fairgrounds

He offered no specifics for how he would achieve that goal. He also continued to criticize Clinton for branding young criminals as 'super-predators' in comments more than 20 years ago.

'Remember that? 'Super-predators,'' he said. 'And they were very, very insulted. But now people have forgotten.' Clinton's primary opponent, Sen. Bernie Sanders, had criticized her for the remark, and she has since apologized for it.

Amid his ongoing appeal to black voters, Trump drew an online backlash Saturday for a tweet he sent in response to the shooting death of NBA star Dwyane Wade's cousin, who was gunned down near the Chicago school where she had planned to register her children.

'Just what I have been saying. African-Americans will VOTE TRUMP!' Trump tweeted. He later sent a tweet offering his 'condolences to Dwyane Wade and his family.'