By Andrew Gray and Andrea Shalal BRUSSELS/EDINBURGH (Reuters) -European Commission President Ursula von der Leyen headed to Scotland on Saturday ahead of a meeting with U.S. President Donald Trump on Sunday afternoon, Commission spokespeople said, as officials from both sides said they were nearing a trade agreement. Trump, in Scotland for a few days of golfing and bilateral meetings, told reporters upon his arrival on Friday evening that he was looking forward to meeting with von der Leyen, calling her a highly respected leader. He repeated his view that there was a 50-50 chance that the U.S. and the 27-member European Union could reach a framework trade pact, adding that Brussels wanted to "make a deal very badly." If it happened, he said it would be the biggest trade agreement reached yet by his administration, surpassing the $550 billion accord reached with Japan earlier this week. U.S. Trade Representative Jamieson Greer and Commerce Secretary Howard Lutnick also departed Washington for Scotland on Saturday to engage in high-level talks with EU officials before the meeting between Trump and von der Leyen, said an administration source who spoke on condition of anonymity. For rolling updates on tariffs, check out our liveblog > "We're cautiously optimistic that there will be a deal reached," the source said. "But it's not over till it's over." The European Commission on Thursday said a negotiated trade solution with the United States was within reach, even as EU members voted to approve countertariffs on 93 billion euros ($109 billion) of U.S. goods in case the talks collapse. EU diplomats say a possible deal between Washington and Brussels would likely include a broad 15% tariff on EU goods imported into the U.S., mirroring the U.S.-Japan deal, along with a 50% tariff on European steel and aluminum. The broad tariff rate would be half the 30% duties that Trump has threatened to slap on EU goods from August 1. To obtain a deal, Trump said the EU would have to "buy down" that 30% tariff rate, although he gave no specifics. He told reporters there was "not a lot" of wiggle room on the 50% tariffs that the U.S. is imposing on steel and aluminum imports, adding, "because if I do it for one, I have to do it for all." It remains unclear if Washington would exempt EU imports from other sectoral tariffs on automobiles, pharmaceuticals and other goods that have already been announced or are pending. Combining goods, services and investment, the EU and the United States are each other's largest trading partners by far. The American Chamber of Commerce in Brussels warned in March that any conflict jeopardized $9.5 trillion of business in the world's most important commercial relationship. (Reporting by Andrew Gray in Brussels and Andrea Shalal in EdinburghEditing by Nick Zieminski and Matthew Lewis)