The European Union and Britain on Friday tripped over the first item in their Brexit talks - protecting the rights of each other's citizens - highlighting the potential for trouble ahead in their marathon negotiations.
While British Prime Minister Theresa May declared that she had offered a "fair and serious" proposal on citizens' rights, European Union chief Donald Tusk dismissed it as falling "below our expectations." Dutch Prime Minister Mark Rutte said "thousands of questions" remained on the key topic.
The 27 EU leaders demanded many more details on the UK proposal to guarantee the rights of the 3 million EU citizens who now live in Britain.
Since many of those citizens will want to stay even as Britain itself leaves the EU, it is an immediate issue where May has a lot of leverage. The British leader is insisting that the EU needs to give the 1.5 million Britons living on the continent equal respect. She will outline a more detailed proposal next Monday, when May addresses her parliament in London.
Alongside citizens' rights, the Brexit negotiators will address the substantial bill that Britain will have to pay to quit the EU and the problems surrounding the border in Ireland.