Sinn Féin says Britain's exit from the EU means it's time to start talking about a border poll on a United Ireland.

56 per cent of the Northern Irish electorate voted to stay in the European Union. Of the region's 18 constituencies, 11 voted Remain and seven voted Leave.

Deputy Sinn Féin leader, Mary Lou McDonald, says a border poll is the only way forward:

In the wake of #Brexit we must think truly nationally of Ireland as a whole and of #IrishUnity pic.twitter.com/PPg5g81RK2

— Sinn Féin (@sinnfeinireland) June 24, 2016

Northern Ireland Secretary Theresa Villiers says the decision to leave the EU will not impact on Britain's role in maintaining peace in Northern Ireland.

She says their commitment to Good Friday Agreement has not been undermined by Brexit:

There are real concerns that Brexit will be bad for business, trade and investment both north and south of the border.

It has also raised the issue of a potential hard border with the north.

Paddy Malone from Dundalk Chamber of Commerce says nobody wants that: