BRUSSELS (Reuters) - The European Union s chief Brexit negotiator Michel Barnier said on Friday it was not possible to put a concrete figure on the amount of money Britain will have to pay the EU upon exiting the bloc because numbers may change in the future.  I have never quoted any figures and will not start today ... because they can change,  Barnier told a news conference. He said he was satisfied with the agreement between the EU and Britain that no EU country, including Britain, would have to pay more or receive less as a result of Britain s decision to leave the bloc in 2019. 