European Union leaders are gathering in Brussels for a two-day summit with an agenda dominated by Britain's drive to leave the European Union.
British Prime Minister Theresa May is due to brief the leaders of the other 27 members later on June 22.
She is expected to offer an agreement on residency for the citizens of the EU countries as well as employment rights in the country.
British and EU negotiators officially started Brexit talks this week. The country is set to leave the bloc by the end of March 2019.
May said upon arrival in Brussels that she will set out plans at the summit to "protect" the rights of European Union citizens living in Britain after Brexit.
"We will be setting out how we propose to ensure that EU citizens living in the U.K. have their rights protected in the United Kingdom," she said.
May is scheduled to also hold a separate meeting with European Council President Donald Tusk, who said on June 22 that he still holds out hope that the Brexit process can be reversed despite the start of the talks. "The EU was built on dreams that seemed impossible to achieve, so who knows?" Tusk said.
But Belgian Prime Minister Charles Michel disagreed with Tusk, writing on Twitter, "It's time for action and certainty. Not for dreams and uncertainty #Brexit #Future of Europe."
Security will be high on the summit agenda following a foiled suicide bombing in the Belgian capital this week and recent attacks in London and Paris.
The Brussels summit also marks the debut on the EU stage of French President Emmanuel Macron.
On the eve of the summit, Macron reaffirmed his belief in a Europe capable of transforming the world with France as a driving force.
In the face of the threats of extremism, inequality and authoritarian regimes, it is up to the European Union to "win the battle" for "freedom and democracy... to ensure social justice and preserving the climate of our planet," Macron said on June 21.
France can play the role of a "driving motor" but only if it first carries out key reforms at home, he said in an interview with eight European newspapers.