Seven countries are candidates or potential candidates for membership in the European Union. Iceland had once been on the list too, but withdrew its application last year.
ALBANIA: Applied for membership in 2009 and was granted candidate status in 2014. The country has been asked to do more to improve the rule of law and the judicial system, fight corruption and organized crime, and protect fundamental rights, including property rights. Detailed accession negotiations are not yet underway.
BOSNIA-HERZEGOVINA: Applied for membership on Monday, after resolving a political stalemate in 2015 that had brought progress on closer EU ties to a halt in the multi-ethnic country. But much work is still needed in the country, EU officials have said. It has been tasked to make progress notably on judicial reforms.
KOSOVO: Five EU member states do not recognize the independence of the former Serbian breakaway province, making EU membership a distant prospect. Despite this, Kosovo and the EU have signed a deal on closer ties, partially as a reward for its progress in normalizing relations with Serbia.
MACEDONIA: Applied for membership in 2004 and was granted candidate status in 2005. The start of accession talks has repeatedly been delayed due to a conflict with Greece over the country's name. A wiretapping scandal and enduring political instability in Macedonia have constituted a further setback.
MONTENEGRO: Applied for membership in 2008, was granted candidate status in 2010 and started accession talks in 2012. Work has begun on several negotiation chapters to bring the country in line with EU standards. Good progress was made on judicial independence and the fight against corruption, but efforts must continue, the EU has said.
SERBIA: Applied for membership in 2009, was granted candidate status in 2012 and started accession talks in January 2014, following progress in normalizing ties with its former province Kosovo. The first negotiating chapters were opened in December. Serbia has been asked to keep pressing ahead with its reform agenda.
TURKEY: Applied for membership in 1987, was declared eligible in 1997 and started accession talks in 2005. Progress has been slow, mostly due to Franco-German opposition and tensions with Cyprus, while the country has also come under increased criticism for its democratic and human rights record. Despite this, the EU has pledged to invigorate the accession talks, in exchange for Ankara's help in stemming migration flows towards Europe.