The European Union's chief Brexit negotiator Michel Barnier warned Thursday that an ongoing deadlock over the financial bill for Brexit had become worrying.

"We are at a deadlock on this question which is extremely disturbing," Barnier said at a news conference with his British counterpart David Davis after the end of a fifth round of talks on Britain's divorce from the EU.

However, he added: "I remain convinced that with political will, major breakthroughs are within reach in the coming two months."