Trump heads to Scotland as 'Brexit' vote result looms
Donald Trump speaks at the Trump Soho Hotel in New York on June 22, 2016 (AFP Photo/Kena Betancur)

Donald Trump takes his first international trip since presumptively clinching the Republican presidential nomination, jumping out of the US political frying pan and into the "Brexit" fire by arriving in Scotland Friday.

The New York celebrity billionaire is scheduled to attend the ceremonial re-opening of his Trump Turnberry golf course on the very day that the British will wake to learn whether they have voted to remain in the European Union or backed the historic move to defect from the 28-member bloc.

With the intense and bitter campaign in Britain coming down to the wire, and Prime Minister David Cameron invoking wartime spirit to call on citizens not to "walk away" from European democracy, Trump repeated his position that the British should leave the EU.

Trump has shocked residents of Britain and Europe with his explosive style, his insult-heavy campaign, and deeply controversial attacks on ethnic and religious groups.

He has pledged to deport millions of undocumented immigrants from the United States, build a wall on the border with Mexico and have that country pay for it.

He has called for a ban on all Muslims entering the United States, a reaction to the migrant crisis in Europe which he has pointed to as fuelling terrorism.

In some ways the trip is reminiscent of Barack Obama's high-profile voyage to Germany in July 2008 before he was president.

Like Trump, Obama was his party's presumptive nominee, having prevailed in a bitter primary battle against Hillary Clinton, but not yet the official party flagbearer.

But Trump stands starkly apart in his approach to Europe. While Obama spoke to a crowd of tens of thousands about his dreams of moving on from the divisive George W. Bush era and wooing a unified Europe, Trump has triggered alarm on the continent.

- 'Go it alone' -

In December Trump blasted Europe's "weak leaders." Three months later, after terror attacks in Brussels, he warned that Europe had "very, very severe" problems with containing extremism.

In May Britain's Cameron blasted Trump's position on Muslims as "stupid, divisive and wrong."

Trump shot back: "It looks like we're not going to have a very good relationship."

On Wednesday he stirred the pot more, proclaiming Europe's migration crisis a "mess" and that while he has not studied the Brexit issue closely, he feels Britain should walk away.

"When you look at the things that are going on over there, my inclination would be go it alone and go back to where you came from," he told Fox News. "That's just my feeling."

Later Wednesday Trump launched a blistering assault on his Democratic rival Clinton, branding her a "world-class liar" and castigating her "disgraceful" record as secretary of state and her policies on trade, foreign policy and immigration.

On Saturday Trump will visit his International Golf Links course in the coastal village of Balmedie, Scotland.

A neighbor of the property, David Milne, is flying a Mexican flag in protest of the real estate magnate's visit.

He says Trump fought with him over the boundaries of their properties, then erected a fence and sent Milne the bill.

Trump said earlier in the month that he would also visit Ireland, but the nation is not on his itinerary.

"We are still in the process of finalizing the schedule and hope to visit Ireland as well," campaign spokeswoman Hope Hicks said. She declined to provide a date.