LONDON (AP) — European Council leader Donald Tusk is due to meet Ireland’s prime minister in Dublin, with the status of the Irish border threatening to derail divorce talks between the EU and Britain.

After Britain leaves the bloc in 2019, the currently invisible 310-mile (500-kilometer) frontier will be the U.K.’s only land border with an EU country.

Britain says it wants to maintain a “frictionless” flow of people and goods with no border posts. But the Irish government questions how that can work if Britain is outside the EU’s customs union.

Ireland says that if Britain doesn’t provide details, the EU will not agree to start discussing future relations and trade.

Irish Foreign Minister Simon Coveney said Friday that Ireland is “uniquely exposed and vulnerable to the consequences of Brexit.”

— Britain has recorded the steepest fall in long-term net migration into the country since records began in 1964, dropping by a third in the year after the vote to leave the European Union, authorities said Thursday.

The figure, which records the difference between the numbers arriving and leaving for a year, was down by 106,000 to 230,000 net arrivals in the year ending June 2017. Some 336,000 were registered in the year ending in June 2016.

More than three-fourths of the reduction was due to EU citizens.

“The number of people immigrating for a definite job has remained stable but there has been a 43 percent decrease in the number of people immigrating to look for work over the last year, especially for EU citizens,” said Nicola White, head of migration statistics at the Office for National Statistics. “These changes suggest that Brexit is likely to be a factor in people’s decision to move to or from the U.K. — but decisions to migrate are complex and other factors are also going to be influencing the figures.”

The ONS said immigration was 572,000, down 80,000, and that the fall included both EU and non-EU citizens. Emigration was 342,000, up 26,000.

Britain’s vote to leave the EU resulted in part from a widespread feeling that unchecked immigration had forced wages down and strained public services. The hotly contested vote also fueled social unease and raised issues of cultural integration, particularly in regard to conservative Muslims. Campaigners for Brexit argued immigration was out of control.

Prime Minister Theresa May’s Conservative government, which has long pledged to cut net immigration below 100,000 a year, said that the new figures show that worries about a “Brexodus” were unfounded. After all, more people are still coming than leaving.

“There is no consent for uncontrolled immigration,” immigration minister Brandon Lewis said. “We welcome the ongoing decrease in net migration levels and remain committed to bringing them down to sustainable levels, the tens of thousands.”

But Jonathan Portes, a senior fellow at The U.K. in a Changing Europe, said the statistics show the country is “less attractive” to migrants from Europe.

“Whatever your views on the impact of immigration, it cannot be good news that the U.K. is a less attractive place to live and work, and that we will be poorer as a result,” he said.