DUBLIN (Reuters) - The border between the United States and Canada does not provide an example for how to solve the issue of the future border between Ireland and Northern Ireland after Brexit, Prime Minister Leo Varadkar said on Monday.

FILE PHOTO: Ireland's Taoiseach (Prime Minister), Leo Varadkar, speaks outside Stormont House, in Belfast, Northern Ireland February 12, 2018. REUTERS/Clodagh Kilcoyne

Northern Ireland is set to become the United Kingdom’s only land frontier with the EU after Brexit, and Varadkar has urged British Prime Minister Theresa May to spell out her proposals to avoid a hard border returning to the island of Ireland.

Speaking in parliament earlier on Monday, May said that her government would look at many examples of different arrangements for customs around the rest of the world, including the border between the United States and Canada.

Varadkar rejected that idea out of hand, however.

“That is definitely not a solution that we can possibly entertain,” he told a news conference after meeting his Luxembourg counterpart Xavier Bettel in Dublin.

“I visited the U.S. border in August and I saw an armored border with physical infrastructure, customs posts and people in uniform with arms and dogs.”

Varadkar reiterated that his preference was to retain the current seamless border through a new, deep relationship between the EU and U.K and was also committed to examining specific British proposals, but only if they are feasible.

If that is not possible, he said the “very clear draft legal provision” to implement a backstop allowing the EU to regulate Northern Ireland’s trade would be triggered.

That contingency plan, presented last week in the EU’s draft of an exit treaty for Britain, prompted angry reactions in London.

Bettel said that Ireland and Luxembourg needed to stand together to reduce to a minimum the negative impact from Brexit, describing it as a “game changer” for the EU that is nothing more than a damage limitation exercise.

He also joined Varadkar in calling on the British government for more detail on its Brexit plans.

“For the moment I can’t tell you what I think about Theresa May’s plans, I want to see them, I want to read them. For the moment I don’t know what the plans are from the U.K,” he said.

“When they were in (the EU), they wanted to have a lot of opt outs, now that they are out, they want a lot of opts ins... I believe we need solutions because the time is ticking.”