British Prime Minister reached out to nationalists and republicans when she referred to Derry as "Derry" in a speech she gave on Brexit in Belfast on Friday.
The Conservative party leader and her government in Westminster are currently trying to negotiate the terms on which they will leave the E.U. but continue to trade with European partners.
The United Kingdom is due to officially leave the E.U. in 2019.
The issue of the border between Northern Ireland and the Republic of Ireland has been a thorn in Theresa May's side since negotiations began.
When the U.K. leaves the E.U. the only land border with an E.U. member state will be in Ireland.
Mrs. May condemned the recent disorder in the Bogside in her speech and said it was not representative of the people living in "Derry/Londonderry".
The British Prime Minister also paid tribute to the late Martin McGuinness and John Hume who she described as playing important roles in delivering the Good Friday Agreement in Northern Ireland in 1998.
Sinn Fein veteran republican, Martin McGuinness, passed away after a short illness in March 2017.
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