There is a 50% chance of a trade deal between the U.S. and the European Union, Donald Trump said Friday as the bloc’s chief Ursula von der Leyen announced a weekend meeting with the U.S. president.

In an attempt to slash his country's trade deficits, Trump has vowed to hit dozens of countries with punitive tariff hikes if they do not hammer out a pact with Washington by August 1.

"I would say that we have a 50/50 chance, maybe less than that, but a 50/50 chance of making a deal with the EU," Trump told reporters before leaving the White House for a trip to Scotland.

His administration promised "90 deals in 90 days" as it delayed the imposition of higher duties in April, but has so far unveiled just five agreements, including with Britain, Japan and the Philippines.

The EU's 27 countries have been allowing the European Commission to focus on seeking a deal to avoid hefty U.S. tariffs, with Trump threatening 30 percent levies without an accord by month's end.