As EU leaders convene in Brussels for a two-day summit, May will meet fellow heads of government for the first time since her party’s poor performance in a snap general election forced her Conservatives to look for parliamentary support from a small Northern Irish regional party.
The Brussels summit will also focus on counterterrorism as well as European defense and security policies.
May will try to reassure the European Council that her minority government will stick to the Brexit process. However, the British leader has a limited timeslot as EU officials intend to relegate Brexit discussions to a lower level.
Separate Brexit negotiations began in Brussels on Monday.
May has insisted her government will not offer any guarantees to EU citizens living in the U.K. without a reciprocal pledge about the future of British citizens living in European states.
“We have always said from the beginning of this that we want to address this at an early stage in the negotiations,” May told British lawmakers on Wednesday.
“We will soon be setting out our offer in relation to European citizens living here in the United Kingdom,” she added.
The U.K.’s policy will be laid out in more detail in a government paper likely to be published next Monday.
The EU has demanded firm guarantees for the around-3.2 million EU citizens living in the U.K., and 1.2 million Britons living in other member states.
Foreign Secretary Boris Johnson earlier described the U.K. move as “a generous offer”.
The European Commission plans to strike a deal with the U.K. which will also guarantee the continuity of freedom of movement under the current rules, which has been enjoyed by millions of Europeans across the continent.
British voters opted to leave the EU in a referendum a year ago and Brexit negotiations are expected to be finalized in March 2019.
The issue of citizens' rights is one of the main issues to be dealt with during the negotiations, together with the land borders between Northern Ireland and the Republic of Ireland as well as Gibraltar and Spain, plus immigration control and access to the European single market.