The head of the WTO also commented on the possibility of a no-deal Brexit.
"If there is what some people call a 'hard Brexit', with no agreement whatsoever, I would say about half of the UK trade would not be affected, because WTO terms are already what applies. In trade with the US, China, Japan, Brazil, Mexico - those terms will not change."
"But of course almost half of trade that is conducted with the UK is with the European Union. So it all depends on the margin of preference and the tariffs that would apply once Brexit comes into effect."