LONDON - President Donald Trump will turn from pageantry to policy Tuesday as he joins British Prime Minister Theresa May for a day of talks likely to highlight fresh uncertainty in the allies' storied relationship.

Trump and May are due to meet with corporate executives from the United States and United Kingdom, before an afternoon news conference on the second day of Trump's state visit. The leaders' top priority is a possible bilateral trade deal to take effect once the U.K. leaves the European Union.

Britain is scheduled to leave the EU on Oct. 31 unless both sides agree to an extension. Its position is in flux because May is stepping down as party leader Friday, setting in motion a race to succeed her as prime minister.