United States President Donald Trump was out playing golf at his course in Turnberry, Scotland on Sunday, ahead of key trade talks with the European Commission President Ursula von der Leyen.

Trump, who is on a private four-day visit to Scotland, arrived from the US at Glasgow Prestwick Airport on Friday evening, with military and police maintaining a major security operation, including road closures.

Hundreds of demonstrators gathered in Aberdeen and Edinburgh on Saturday to voice their opposition to Trump's visit.

Soon after arriving in Scotland, the president criticized European policy on wind turbines and immigration, telling reporters, there won't be a Europe unless they "get their act together".

"I say two things to Europe. Stop the windmills. You're ruining your countries," he said, describing turbines "ruining your beautiful fields and valleys and killing your birds".

"On immigration, you better get your act together," he added. "You're not going to have Europe any more."

Intensive negotiations were held on Saturday between European Union and US officials ahead of the meeting with von der Leyen, The Guardian newspaper reported.

On a possible trade deal, Trump identified "20 sticking points" but declined to elaborate. "Well, I don't want to tell you what the sticking points are," he told reporters.

He praised the EU chief as a "highly respected woman", and predicted their talks would be "good", and rated deal prospects as "a good 50-50".

The Guardian reported that any deal would focus on a 15-percent export tariff for vehicles while maintaining 50 percent on steel imports.

A potential pharmaceutical deal could set medicine export rates at 15 percent, which would violate a World Trade Organization agreement that medicines are rated at a zero tariff.

Von der Leyen's spokesperson, Paula Pinho, said: "Intensive negotiations at technical and political level have been ongoing between the EU and US.

Leaders will now take stock and consider the scope for a balanced outcome that provides stability and predictability for businesses and consumers on both sides of the Atlantic."

Trump is due to meet United Kingdom Prime Minister Keir Starmer on Monday, for further talks on the preliminary trade deal agreed between the UK and US in May.

Starmer is expected to press Trump on reviving Israel-Hamas ceasefire talks during their meeting in Scotland, reported The Times newspaper.

The push comes after US and Israeli teams withdrew from Qatar negotiations this week, with Washington's envoy Steve Witkoff citing Hamas's "lack of desire to reach" a deal.

Starmer held emergency discussions on Saturday with French President Emmanuel Macron and German Chancellor Friedrich Merz, agreeing the need for "robust plans to turn an urgently needed ceasefire into lasting peace".

Before he departs on Tuesday, Trump is scheduled to meet Scotland's First Minister John Swinney and open a second 18-hole golf course, at his Aberdeenshire estate. The president is due to return to the UK for an official state visit in September.