The European Union has formally opened accession talks with Turkey, despite a last-ditch objection from Cyprus.
Some EU leaders are lukewarm about Turkey's bid
A first round of talks, on science and research, was concluded on day one of negotiations, sealing the first of 35 policy areas scheduled for discussion.
Talks on all 35 "chapters" are expected to take about 10 years.
Cyprus had asked the EU to press Turkey for official recognition and to open ports to Cypriot shipping, forcing the EU presidency to broker a late deal.
Turkey had threatened to boycott the meeting of foreign ministers in Luxembourg unless Cyprus - divided since 1974 - agreed to compromise.
Austrian Foreign Minister Ursula Plasnik, whose country holds the EU presidency, said concluding the first chapter was "not an easy matter".
"We've made a start, it's the first step along a path where every step will have to be approved by every EU member," she said.
The EU did go some way towards accepting Cyprus' demands.
The EU text reminds Turkey that "failure to implement its obligations in full will affect the overall progress in the negotiations".
Cypriot Foreign Minister George Iacovou described the debate over the first chapter as a "good loud and clear warning shot".
The science and technology chapter of the talks are regarded as the easiest of the 35 policy areas, all of which need to be fulfilled for Turkey's membership bid to succeed.
Cyprus joined the EU in May 2004, despite the fact that it has been divided since 1974.
The split came when Turkey occupied the northern third of the island, following an abortive Greek Cypriot coup backed by the military junta ruling Greece at the time.
A UN "green line" separates Greek and Turkish Cypriots
Turkey says recognition of Cyprus is linked to a UN-sponsored peace plan to reunite the island, which Turkish Cypriots accepted but Greek Cypriots rejected in 2004.
The EU agreed last October to launch talks on Turkey's membership bid - but the deal followed more than 24 hours of intense negotiations among EU members.
The BBC's Jonny Dymond in Luxembourg says everyone knew that Turkish membership negotiations would be difficult - but no-one thought they would be so tough so soon.
Turkey feels more and more that many in the European Union are not serious about its membership bid, he says.
The EU has prepared a report critical of Turkey's reform process. That will be poorly received by the Turkish government, our correspondent adds.
In other business the ministers:
- Formally recognised Montenegro as a sovereign independent country, in line with the country's recent independence referendum
- Concluded talks on the first policy "chapter" - science and technology - with Croatia, which like Turkey is seeking EU membership
- Signed an agreement on closer trade and political ties with Albania - a Stabilisation and Association Agreement, often seen as the first step towards eventual EU membership.