A 'friction free' border was the target set by Enda Kenny and Theresa May during their Brexit meeting that was largely overshadowed by events in the United States.
Both prime ministers faced a series of questions over their engagements with US President Donald Trump on a day when they hoped to show some progress on building a post-Brexit understanding.
Mr Kenny described their discussions as "frank" but indicated that Ireland would be working to help Britain retain some trading rights after they leave the EU, while Mrs May said "everyday movements" across the Border must remain "seamless".
However, it was the turbulent global climate in the wake of Mr Trump's 'Muslim ban' that dominated their joint press conference with Mr Kenny confirming he will accept the traditional St Patrick's Day invitation to the White House.
And the British prime minister insisted that despite a public backlash, her offer of a state reception for Mr Trump in London stands.
Mr Kenny said: "It's really important that I be able to say face-to-face to the president the issues that are of importance to us."
He added that while he disagrees with the new administration's immigration policy, he has to go to Washington to speak for Irish citizens living in America, including about 50,000 undocumented immigrants.
"I don't agree with it - I will obviously say that to the president and vice president when I meet with them," Mr Kenny said.
Mrs May was blunt in her response when asked whether it was appropriate for the UK government to welcome the new president at a time when he is enforcing such a ban on citizens from seven countries.
"That invitation stands," she said.
Mrs May said the US "is a close ally of the UK" but "we have a different approach to these matters in the UK".
On Brexit, Mr Kenny said a deal to keep UK-EU trade as close as possible would be an "absolute priority" for Ireland.
"Our two governments are agreed that a close and friction-free economic and trading relationship between the United Kingdom and the European Union, including Ireland, is in our very best interests," the Taoiseach said.
"And as the UK prepares for its formal notification under Article 50, we want to see that these deep trading ties between our two countries are recognised and facilitated.
"That will continue to be an absolute priority for my Government, not just in our discussions with the British government, but also with our EU partners as we prepare for the negotiation process on the EU side of the table."
For her part Mrs May promised to try to retain a situation whereby residents of the Republic and Northern Ireland will be able to freely pass over the Border daily without interruption.
She noted that Britain and Ireland had open borders "long before either of us was a member of the European Union".
"We have of course said we do not want to see a return to the border of the past - that isn't just a phrase, actually it symbolises the sort of seamless, frictionless border that we want to see in the future," Mrs May said.
"Of course there are elements of full membership of the customs union that would restrict our ability to trade and do trade agreements with other parts of the world.
"But I believe, and this is what we are working on, that we need to find a solution which enables us to have as seamless and frictionless a border as possible between Northern Ireland and Ireland so that we can continue to see the trade, the everyday movements, that we have seen up to now," she said.
Ireland's relationship with the United States dates back to before the independence of either country. It is built on the hundreds of thousands of our people who left for a new life in the US, whether fleeing famine or conflict at home or seeking better economic opportunity.
It doesn't really matter that the seven countries affected by US President Donald Trump's new immigration rules - Syria, Yemen, Somalia, Iraq, Iran, Libya and Sudan - had previously been earmarked by Barack Obama for special immigration measures.