European Commission President Ursula von der Leyen on Friday warned Great Britain that it could not have it all in negotiations on future relations with the EU and that it had to decide how close it wanted to stay to the EU, which it will leave on January 31.
We were clear regarding access to the common European market - it is not the same if you are a member or not, the EC president said at a news conference in Zagreb.
We want to stay good friends, neighbours and partners but we must find a good balance between divergence and close relations with the single market, she added.
British Prime Minister Boris Johnson is confident that the agreement on all aspects of future cooperation with the EU can be concluded by the end of 2020, which EU officials consider unrealistic.
Croatian Prime Minister Andrej Plenkovic said that nothing would change for Croatian citizens on January 31.
"You will be able to enter Great Britain as you have so far," said the PM of Croatia, the EU chair since January 1.
Along with Brexit, an important topic during Croatia's EU presidency will also be talks on the new European budget.
"We will do our best to find a balance between rural development and cohesion on one side and modernisation on the other," said Plenkovic.
The older EU members, which are net contributors to the EU budget, want it to be more modest while the younger members insist on maintaining funding for the cohesion and agriculture policies.
Balance must also be found between EU bodies as the European Parliament calls for a more ambitious budget while the prime ministers of European Council members want a more conservative budget.
With Great Britain's departure, Europe will lose around €60 billion from its cash register, and the new financial perspective for the 2021-2027 period will have to take account of new European priorities such as climate change, the digital agenda and illegal migrations.
Von der Leyen and Plenkovic addressed reporters after a joint session of the EC and the EU chair's government, which is a tradition at the start of every rotating EU presidency.