BRUSSELS (AP) — European Union chief Donald Tusk says Britain needs to come up with much more concrete proposals to reinvigorate stalled Brexit negotiations.

The European Council president said Wednesday that for the two sides to meet the goal of completing the first phase of talks by year's end, Britain must translate the intentions Prime Minister Theresa May has outlined into negotiating positions.

Tusk says he is "absolutely sure it is still possible to achieve this final first phase in December but for this we need more concrete proposals from the British side, to be honest."

May made a conciliatory speech in Florence last month in which she proposed a transition period for Britain's departure from the EU.