ANKARA - The European Union's top envoy to Turkey has resigned, EU officials said on Tuesday, in a further sign of strained relations as Brussels tries to keep a deal credited with curbing the flow of illegal migrants to Europe on track.
Hansjoerg Haber's resignation comes a month after he was summoned by Turkey's foreign ministry over comments critical of Ankara's handling of the migration accord. An EU official said his departure was "not for personal reasons".
The 28-nation EU is dependent on Turkey to enforce a deal, criticised by rights groups, that has sharply cut the number of refugees and migrants reaching Greece, giving EU leaders breathing space after more than a million arrived last year.
But the bloc is treading a difficult line, facing accusations of compromising its values by failing to be critical enough of Turkey's deteriorating record on rights and freedoms.
A spokeswoman for the European Commission said Haber would be leaving his role as of August. "The successor will be appointed swiftly. We as the European Union continue to work with Turkey, Turkey is a key partner, it's a candidate country. We have renergised our relationship," spokeswoman Maja Kocijancic said.
She declined to give any reason for the resignation.
Haber was summoned by Turkey's foreign ministry in May to complain about comments he had made about the migration deal.
Turkish officials took offense at his use of an unflattering German saying, cited in local newspapers, to describe how a plan to ease visa restrictions for Turks travelling to Europe, part of the wider migrant deal, had run into problems.
Turkey and the EU have been discussing visa liberalisation since 2013 and agreed in March to go ahead with it as part of the deal to halt illegal immigration from Turkey to the EU.
But progress stalled when Brussels insisted that Ankara must also reform its tough anti-terrorism laws.
Prime Minister Binali Yildirim repeated on Tuesday that Turkey had no intention of changing its anti-terrorism laws, even if that meant the deal on visa-free travel collapsing.
The EU says Turkey must narrow its definition of terrorist crimes, which leads to extensive application of the law against intellectuals, Kurdish sympathisers and critics of President Tayyip Erdogan, including journalists and academics.
Turkey says its laws are crucial to its fight with Kurdish and Islamic State militants.
Officials on both sides have said agreement on visa-free travel for Turks, unpopular in many EU states, is now unlikely until the autumn at the earliest.