Those include paying tens of billions of euros and giving residence rights to some 3 million EU citizens in Britain, the proposed negotiating objectives distributed by EU summit chair Donald Tusk to Britain's 27 EU partners showed.
Maltese prime minister Joseph Muscat, whose country now holds the European Union presidency, said Brussels would draw up a "clear balance sheet" of what Britain owes.
On Wednesday, the Prime Minister set out her priorities for Brexit talks in a letter which triggered Article 50, in which she said divorce talks and free trade talks should take place at the same time.
European officials suggested enough progress could be made on the divorce arrangements by the end of the year to begin trade talks, although EU leaders will have the final say.
The European Union will wait until the conditions of the UK's exit from the EU have been agreed before talking about the country's future relationship with the trading bloc, François Hollande told Theresa May.
The EU's opening gambit in what Mr Tusk said would at times be a "confrontational" negotiation with Mrs May's government also rammed home Brussels' insistence that while it was open to letting Britain retain some rights in the EU during a transition after 2019, it would do so only on its own terms.
Tusk said progress will be determined by the European Council and that he hopes that could be achieved "in the autumn".
In France's Le Parisien newspaper May underlined the importance of "the closest possible security cooperation" after Britain leaves the EU.
Tillerson: Russian response to strikes disappointing, unsurprising
In addition, a bomb killed one woman and wounded 25 others in the city of Homs, officials said. But there have been repeated allegations of chemical weapons use by the government since then.
Setting out the guidelines, Tusk said it was "only fair" that the United Kingdom should honor the financial promises it made as part of the 28-member bloc.
Maltese Prime Minister Joseph Muscat, who is the incumbent rotating EU President, appeared alongside Tusk at the conference and said the Brexit negotiations will be tough but "it will not be a war".
Johnson, speaking in Brussels upon arrival for a North Atlantic Treaty Organisation meeting Friday, said he has had good feedback from partners since Wednesday's British announcement, despite worries on both sides of the Channel about Brexit.
It had called for simultaneous talks on exit terms and future trade ties.
His guidelines - which are expected to be formally adopted at an European Union summit at the end of April - are expected to endorse the position of France and Germany that trade talks must wait until the separation has been agreed.
"The EU 27 does not and will not pursue a punitive approach".
However, they expect that the references to Ireland, the northern peace process and the Border will chime with the positive approach taken by Michel Barnier, the commission's lead negotiator, and with the language used by British prime minister Theresa May this week.
Mr Tusk said it was "only fair" the United Kingdom should honour the financial promises it made as part of the 28-member bloc. "That process starts now", Davis said in a statement.