First Minister Arlene Foster has welcomed the Prime Minister's announcement that formal Brexit negotiations will get under way by the end of March 2017.
Speaking after Theresa May's confirmation that she will trigger Article 50 next year, Mrs Foster said she would work to secure the best deal for Northern Ireland.
“I welcome the announcement from the Prime Minister that our formal exit processes will commence before the end of March," said Mrs Foster.
"I spoke with Brexit Secretary of State David Davis MP last evening and we agreed that it was important that the Government work closely with us throughout this process.
"Today’s announcement on when Article 50 will be triggered as well as the intention to repeal the European Communities Act 1972 brings further clarity to the process of exiting.
"The DUP fought a leave campaign not just in Northern Ireland but also across the whole of the United Kingdom. We played a key role in the campaign.
"I believe the decision to leave the European Union is in the best interests of the United Kingdom. However it is important to collectively work to secure the best deal for Northern Ireland as the exit process commences next year. It is important to maximise our opportunities as well as overcoming the challenges unique to Northern Ireland.
"I make no apologises for saying that I will be working to secure the best exit deal for Northern Ireland and I will work alongside other parties, despite our differences on the referendum outcome, to get that deal for our people.
"There are huge opportunities for Northern Ireland and United Kingdom collectively and we want to make the most of them.
"I look forward to travelling to Birmingham on Tuesday for further discussions.”
Steve Aiken MLA, the Ulster Unionist Party's economy spokesperson, said the Executive has "nowhere left to hide" and called for a credible plan to be urgently put together.
“Now that the Prime Minister has given clear notice that Article 50 will be triggered before the end of March 2017, there is a huge onus on the Northern Ireland Executive to urgently pull a credible plan together so that the unique challenges facing us are addressed as part of the UK's negotiations with the EU," he said.
“The Executive now has nowhere left to hide and the clock has started counting down. Their approach so far has been lamentable, marked by mixed messaging and a complete lack of urgency. We need to exploit the opportunities presented by Brexit but if we're not careful we could be left behind."
He added: “Perhaps First Minister Foster will be able to offer some clarity while she is sipping champagne at the Conservative Party Conference.”