Theresa May hopes to resolve the residency rights row between the UK and EU at an "early stage" of the Brexit negotiations, the Conservative premier told MPs on Wednesday (30 November).
The UK prime minister made the comments just a day after European Council President Donald Tusk stressed that the issue would not be formally discussed until May triggers Article 50, the official mechanism to split from Brussels.
The British leader has promised to start the talks by March 2017, but the timeline could be pushed back after England's High Court ruled that MPs must have a vote on Article 50.
The government are contesting the decision at the Supreme Court from 5 December, with a ruling expected in January 2017.
"I would think this is an issue that we can look at an early stage of the negotiations," May said. "Of course, there will be two years of negotiations...I think it is right that we give reassurance to British citizens living in the EU and to EU citizens living here in the UK.
"But I think the reaction that we've seen shows why it was absolutely right for us not to do what the Labour Party wanted us to do, which was simply to give away the guarantee for rights of EU citizens here in the UK because as we have seen that would left UK citizens in Europe high and dry."
The remarks were in reply to Conservative MP Michael Tomlinson during Prime Minister's Questions (PMQs). Tomlinson, along with 52 other pro-Brexit MPs, had demanded the European Council guaranteed residency rights for UK citizens on the continent.
"Just like you, I would like to avoid a situation where citizens become 'bargaining chips' in the negotiation process," Tusk said. "In order for this not to happen, we will need precise and comprehensive solutions, which, other than nice-sounding expressions, will provide citizens with genuine guarantees of security."
German Chancellor Angela Merkel also reportedly "rebuffed" May over the issue when the leaders met in Berlin on 18 November.
Guy Verhofstadt, the EU Parliament's chief Brexit negotiator, also refused to engage in "hypothetical questions" when IBTimes UK pressed him on the residency rights issue.
More than three million EU nationals live in the UK, while more than 1.2 million Britons reside in the other 27 EU nations.