UK Secretary of State for Exiting the European Union David Davis (L) and the European Commission's Chief Brexit Negotiator Michel Barnier talk to reporters at the start of a first full round of talks on Britain's divorce terms from the European Union, in Brussels, Belgium, July 17, 2017. [Photo/Agencies]

BRUSSELS - EU and British negotiators found some common ground at the end of a first full round of Brexit talks but big differences remain over citizens' rights and uncertainty persists over the financial settlement and the Irish border.

At the end of four days of talks in Brussels, which focused on setting out positions on key issues, the European Union's chief negotiator Michel Barnier said there was "a fundamental divergence" on how to protect the rights of EU citizens living in Britain and of Britons in the EU after Brexit.

He insisted that the European Court of Justice should guarantee citizens' rights after Brexit.

"Any reference to European rights imply their oversight by the Court of Justice of the European Union," Barnier told a joint news conference with British Brexit Secretary David Davis.

He also called for more clarity on the British position on the financial settlement and on the Irish border.

Davis saw "progress" after talks and said the meetings in Brussels this week provided "a lot to be positive about".

But he refused to confirm that Britain now accepts that it will end up making some kind of net payment to the EU on leaving.

"We're a country that recognizes its international responsibilities and rights and that we will seek to exercise both in the future," he said.