BRUSSELS, Oct 15 (Reuters) - European Union leaders agreed on Thursday to keep on talking to Britain to get a new trade agreement "in the coming weeks" but also decided to step up their contingency preparations should the troubled negotiations fail.

National leaders of the 27-member bloc meeting in Brussels to discuss Brexit said in a joint decision they would "continue negotiations in the coming weeks" and called on Britain "to make the necessary moves to make an agreement possible".

They also stressed the EU's earlier divorce with Britain must be fully implemented by the end of the year, a reference to a new draft UK law known as the Internal Market Bill. If approved, it would undercut parts of Britain's Brexit settlement.

(Reporting by Marine Strauss, Writing by Gabriela Baczynska, Editing by Catherine Evans)