EU "enlargement fatigue" is a worry for candidate countries
The European Commission says Croatia is on track to wrap up EU accession talks next year and could be ready to become the bloc's 28th member state in 2011.
But Croatia will have to work hard to tackle corruption and organised crime, the commission says, noting recent high-profile mafia-style killings.
In an annual report on applicant countries, the commission also urged Macedonia and Turkey to boost reforms.
The EU says Turkey must do more to entrench political freedoms.
The EU's enlargement commissioner, Olli Rehn, says Ankara needs to strengthen press freedom, women's rights and gender equality.
'Not a blank cheque'
Turkey started EU entry talks in 2005, along with Croatia, but major stumbling blocks remain, including Turkey's failure to normalise relations with EU member Cyprus.
Responding to the EU report, Turkey's foreign ministry described EU membership as "a strategic aim" and said "we are fully determined to implement the political and economic criteria".
The report, released on Wednesday, criticised Macedonia after a flawed general election in June.
But the prospect of becoming a candidate member next year will be held out to Serbia, if it can deliver fugitive Bosnian Serb wartime general Ratko Mladic to the UN war crimes tribunal in The Hague.
Mr Rehn also said the challenge for Bosnia-Hercegovina's leaders "is to achieve the degree of political consensus that has delivered progress on EU integration elsewhere in the region".
He regretted a recent "deterioration of the political situation" in Bosnia-Hercegovina.
The commission's "roadmap" for Croatia is "an encouragement, but not a blank cheque," Mr Rehn said, adding that "the ball is now firmly in Croatia's court".
A prominent newspaper editor and his marketing chief were killed by a car bomb in Zagreb last month. In another recent high-profile murder, the daughter of a prominent lawyer was gunned down in the Croatian capital.
France and Germany say any talk of EU accession dates is an empty promise, unless the EU finds a way to revive the Lisbon reform treaty, meant to prepare the bloc for new members.