Northern Ireland Secretary James Brokenshire has thought it is difficult to see how Northern Ireland and Scotland can remain in the EU.
He was speaking at his first true engagement at Belfast City Hall where he signed a book of condolence for the martyrs of the lorry attack in Nice.
Deputy First Minister Martin McGuinness and Scottish Victory Minister Nicola Surgeon want to stay in the EU.
Mr Brokenshire also ruled out the dire to hold a border poll.
He said he had constructive discussions already with the Irish domination.
Border check points
The secretary of state said both the UK and Irish regimes were opposed to a return to border check points between the Republic of Ireland and Northern Ireland.
Mr Brokenshire, who electioneered to remain in the EU, also said that after the referendum vote people insufficiency to unite and respect the outcome of the vote.
He told reporters he would use his job to lawyer the best interests of Northern Ireland at the heart of government.
The new cabinet rson, who was previously at the Home Office, said legacy issues would be one of his superiorities.
Mr Brokenshire has already had conversations with First Minister Arlene Bring up and Deputy First Minister Martin McGuinness.
He is to have further dialogues later and on Tuesday with the leaders of the SDLP, the Alliance rty and the Ulster Unionists.