Speaking on Saturday, after Friday's EU summit in Brussels he called on the British government to lay its cards on the table and he stressed the need for speed.
Donald Tusk said: "There is a great deal of work ahead , and the most difficult tasks are still unresolved. If you want to reach a deal in October we need quick progress. This is a last call to the British government to lay the cards on the table."
However, UK Prime Minister Theresa May, who left Brussels early on Friday morning, agreed on the need to speed things up, but insisted that applies to both parties.
Theresa May said: "I've been stressing that we want a deal that's going to work for the UK and for our European partners and that if we work together we can support each other's prosperity and security. Now we're going to be publishing our white paper shortly and I want to see the negotiations accelerating and intensifying thereafter. We are ready to intensify and accelerate the pace of negotiations. I want to see that from the European Commission and the European Union as well."
