Stormont Infrastructure Minister Nichola Mallon has expressed "surprise and disappointment" after she was not consulted about proposals for a bridge linking Scotland and Northern Ireland.
She said: "I am requesting clarity on exactly what is proposed by British Government ministers and I would also welcome an explanation as to why ministers and officials here have not been contacted or consulted in advance of the announcement.
"I also want to make clear that significant investment is needed in our infrastructure and the New Decade: New Approach document makes several key commitments on behalf of the British Government, which I also expect to see honoured."
It comes as Scottish Transport Secretary, Michael Matheson, has called for urgent talks with the UK Government over the proposals - an idea he described as the Prime Minister's "vanity project".
In a letter to UK Transport Secretary Grant Shapps, Mr Matheson said he wants to express concern after discussing the proposals outlined earlier this week with his Northern Irish counterpart Nichola Mallon.
Boris Johnson has said work is under way to assess the feasibility of a bridge between Portpatrick and Larne - estimated to cost £20 billion.
First Minister Nicola Sturgeon has called for the money to instead be sent to Scotland and Northern Ireland to be spent on infrastructure projects.
In his letter, Mr Matheson said there have not been any discussions with the Scottish or Stormont administrations, despite transport being devolved.
"I therefore request immediate discussions with your officials on releasing to us the £20 billion of funding you have identified so it can be invested in the priorities of Northern Ireland and Scotland," Mr Matheson said.
"Given transport is devolved to both the Scottish Government and Northern Ireland Executive, I look forward to hearing from you on the availability of the £20 billion to us, and to assurances that in future any such proposals will be discussed with us first and will fully respect the devolved settlements and the role of the Northern Ireland Assembly and the Scottish Parliament."
Mr Matheson also raised concern about a reported "munitions dump" at Beaufort's Dyke in the Irish Sea, on the path of construction for the proposed bridge, saying money spent to work around the problem "could be put to better use on practical, deliverable projects".