President Barack Obama leaned in further on his warning to the British electorate against embracing a so-called Brexit from the European Union, saying it could take as long as 10 years before the U.K. and the U.S negotiated a new trade agreement.

'The U.K. would not be able to negotiate something with the United States faster than the EU," Obama told the BBC in an interview published on Saturday. "We wouldn't abandon our efforts to negotiate a trade deal with our largest trading partner, the European market. But rather, it could be could be five years from now, 10 years now before we were actually able get something done."

The president's remarks were the most detailed he's made yet in addressing the argument that a Brexit would hurt the British economy by delaying its ability to ink a trade deal with the U.S. Obama, who said Friday that Britons would be at the "back of the queue" in negotiating a trade agreement with the U.S. separately from the EU, indicated that the queue may last a decade.