The UK and Ireland have signed an agreement to protect the rights of both Irish and British citizens "in all circumstances" after Brexit.
Tánaiste Simon Coveney and Theresa May's de facto deputy prime minister David Lidington signed the Memorandum of Understanding in London earlier today.
It recommits to the existing Common Travel Area (CTA) arrangements and pledges that they will continue whether the UK leaves the EU with or without a deal.
It means British and Irish citizens will not need to do anything to protect their existing status and rights after Brexit.
We have signed a Memorandum of Understanding with the Government of Ireland reaffirming our joint commitment to the Common Travel Area, ensuring British and Irish citizens will continue to have the right to move freely in each country.May 8, 2019
Citizens in both countries will continue to enjoy existing social security entitlements, while all citizens have access to all levels of education and training in either jurisdiction.
Healthcare and immigration arrangements will also continue as normal.
Minister Coveney said the signing of the new agreement marks an "important moment" for the Common Travel Area.
He observed: "Many of us have personal experience of the CTA in our daily lives. This MOU demonstrates and confirms the commitment of both Governments to maintaining the CTA in all circumstances.
"British citizens will continue to be able to travel freely, live, study, and work in Ireland into the future.
"I welcome the similar commitment and welcome of the UK Government for Irish citizens in Britain."
He added that the CTA also underpins the Good Friday Agreement "in all its parts".
The Common Travel Area predates the two countries' membership of the EU, but arrangements between other member states and the UK will likely change somewhat once Brexit has taken place.
While the withdrawal agreement between the EU and UK makes provisions to protect citizens' rights, MPs in the House of Commons have rejected the agreement several times.
However, the UK government has previously insisted that EU citizens and their family members will be "welcome to stay in the UK in the unlikely event of a ‘no deal’ scenario".