LONDON – The Prime Minister of the United Kingdom on Friday gave a speech on Brexit in which she acknowledged that such is the nature of negotiations that neither side will walk away with exactly what it wants, but she remained optimistic that a comprehensive future deal could be struck to benefit both London and Brussels.

At a briefing in London, Theresa May brought the media up to speed on her Conservative government’s approach to Brexit and said both sides of the negotiating table had to face up to several hard facts.

“We’re leaving the single market. Life is going to be different. In certain ways our access to each other’s markets is going to be less than it is now,” the Tory leader said. “This is a negotiation and neither of us can have exactly what we want,” she added.

On that same concessional note, she advocated for binding deals to be struck with the EU in certain areas so that the UK could remain a part of prominent agencies such as the European Medicines Agency and the European Aviation Safety Agency.

She acknowledged, too, that the European Court of Justice would still have an impact on the UK post-Brexit, given that it has the power to dismiss a bilateral deal that does not meet EU standards and regulations.

On other points, she was less flexible, however. The PM adamantly dismissed a recent proposal from the EU to keep Northern Ireland in a customs union in order to maintain a soft border with the UK territory’s southern neighbor, EU member state the Republic of Ireland.

The open border between the two territories was enshrined in the 1998 Good Friday Agreement that put an end to decades of sectarian conflict in the region.

“As Prime Minister of the whole United Kingdom, I am not going to let our departure from the European Union do anything to set back the historical progress made in Northern Ireland. Nor will I allow anything that will damage the integrity of our existing union,” she said.

Both a hard Irish border and a trade barrier in the Irish sea would be unacceptable solutions to the issue, which has been a sticking point in the Brexit negotiations so far.

Turning to the matter of trade, May defended the UK’s ambitions to land a commercial deal with the EU that went beyond those struck by Canada and South Korea.

This position has been repeatedly dismissed by the EU as cherry picking, but May was insisting that all trade deals involve an element of cherry picking.

The UK is on track to leave the bloc on March 29, 2019, although public pressure has mounted on the Conservative government to clarify its stance on the procedure.