Both Ireland and Britain are seeking a solution to avoid a hard border between Ireland and Northern Ireland - which is part of Britain - after Brexit.
The head of the WTO says it would not be "the end of the world" if Britain failed to reach a post-Brexit trade deal with the EU, but there would be costs.
Senior British ministers have agreed to offer more money to Brussels as part of Brexit negotiations, but only as part of a final deal on leaving the EU, sources say.
Follow us, or the US! - EU chief negotiator Michel Barnier offers hope of an "ambitious" free trade deal but warns the UK must adhere to EU not US rules after Brexit.
European Union member states want to improve "the exchange of information," they said after a meeting Tuesday.