"Our job is not to deal with Brexit in theory but make a success of it in practice for all of our people. And nowhere is the need for practical solutions more vital than here in Northern Ireland — the only place where the United Kingdom shares a land border with an EU member state that is also a co-signatory to the Belfast agreement," Mrs. May said.
As the United Kingdom and the European Union are in talks over the Brexit deal, both parties have agreed there should be no hard border in Ireland after Brexit.
Any Brexit agreement would have to provide frictionless trade across Northern Irish border, May said in her speech. She hailed the White Paper produced by the government on the future relations between Britain and the EU.
Mrs. May also spoke about the value of the UK union and its potential for the future.
"Right across the UK far more unites than divides us," she added.
"As we leave the European Union and go out to strike new trade deals around the world, open up new markets for the products and services of our innovators and entrepreneurs. As we face the challenges of the future together and draw on the talents and resources of every part of the United Kingdom to overcome them — and that of course includes Northern Ireland," she added.
Theresa May said she wants to see the Northern Irish government formed again, referring to collapse of the power-sharing executive in Belfast made up of the DUP and Sinn Fein political parties in January 2017.
"It is a matter of frustration and regret that after a long period unbroken devolved government since the 1960s, Northern Ireland has now been without a fully-functional executive for over 18 months. I want to see the executive and the assembly back up and running, making decision on behalf of all the people in Northern Ireland."
The Friday speech in Belfast provided the PM with an opportunity to urge the European Union leaders to take a more flexible view on how to solve the Irish border issue.
"It is now for the EU to respond, not simply to fall back on previous positions which have already been proven unworkable but to evolve their position in kind," Mrs. May said.