Peace in Northern Ireland cannot be a bargaining chip in Brexit negotiations, the Irish Government has warned.
As Britain stated that its number one priority was keeping the Irish border free of checkpoints, leaders in Dublin said that avoiding a return to the paramilitary violence and terrorism of the past is crucial.
"The emphasis on the priority areas identified by the Government, including the Common Travel Area, the Good Friday Agreement, north/south cooperation and avoiding a hard border, is welcome," an Irish Government spokesman said.
"Protecting the peace process is crucial and it must not become a bargaining chip in the negotiations."
The policy paper on the border between Ireland and the UK dismissed the possibility of shifting checks and tariffs to the Irish Sea.
The document also stated that a so-called "hard border", with physical infrastructure or checkpoints on roads and rail linking the Republic and Northern Ireland, should also be avoided.
The Irish Government said the paper from London's Department for Exiting the European Union is "timely and helpful" as it offers more clarity.
It said it would analyse the ideas on the border and customs in detail and discuss them with the European Commission and Brussels chief negotiator Michel Barnier.
"The immediate focus for the coming rounds of negotiations remains on advancing the issues identified for phase one of the negotiations, including citizens' rights and the financial settlement, as well as issues specific to Ireland," the Government spokesman said.
"The Government remains hopeful that there will be sufficient progress on these issues to allow the necessary parallel discussions on the future relationship between the EU and the UK, including in relation to customs, to commence."