AFP Copyright: AFP Donald Tusk wants a serious response from the UK Image caption: Donald Tusk wants a serious response from the UK

European Council President Donald Tusk has called on the UK to come up with a "serious response" on what will happen to EU citizens in Britain after Brexit.

"We need guarantees," he said in Brussels, as 27 EU leaders backed the bloc's Brexit negotiating guidelines.

The rights of EU citizens to live, work and study in the UK is one of three topics they want dealt with in the first phase of Brexit talks.

Negotiations will start after the UK election on 8 June.