One of the smallest countries in Europe has warned against member states going their "separate ways".
EU states should work in solidarity to face up to serious economic and social challenges, according to Luxembourg's foreign minister, Jean Asselborn.
Voters in Scotland will be asked whether to back independence from the rest of the UK in autumn next year.
Prime Minister David Cameron has called for an in/out referendum on the UK's place in the EU if the Conservatives win the next general election.
In a statement reported by the BBC, Mr Asselborn said: "As we are all facing serious economic and social challenges, this is a time for solidarity between member states of the EU and within member states rather than for going separate ways."
Luxembourg has a population of about half a million people and is bordered by Germany, France and Belgium.