Britain - which is excluded from the summit - announced on Monday it will formally trigger negotiations to exit the EU on March 29.
Brussels: The 27 European Union nations will hold a special Brexit summit on April 29 - one month after Britain plans to trigger divorce proceedings with the EU - to decide on the guidelines for the next two years of negotiations with the UK.
EU Council President Donald Tusk said on Tuesday that the "Brexit guidelines" aims to give citizens, companies and all member states "certainty and clarity" on how the talks will go.
Britain - which is excluded from the summit - announced on Monday it will formally trigger negotiations to exit the EU on March 29. That is expected to create two years' uncertainty for all sides because no member state has ever walked away from the bloc.
"We must do everything we can to make the process of divorce the least painful for the EU," Tusk said.
The two sides will have until March 2019 to agree on a divorce settlement and - if possible - establish a new relationship between Britain, the world's No. 5 economy, and the EU, a vast single market containing 500 million people. If both sides agree, the negotiating deadline can be extended.
Britons voted in a June referendum to leave the EU after more than 40 years of membership.
Tusk stressed again how unfortunate he thought it was for Britain to leave, but said that the first task now was "to create as much certainty and clarity as possible for all citizens, companies and member states that will be negatively affected by Brexit, as well as our important partners and friends around the world."
The summit will give EU negotiator Michel Barnier a framework to deal with the British side. Tusk is expected to make his proposals for the guidelines before the end of the month.