The head of the European Commission said it will make a proposal to Turkey to ensure the flow of funding for refugees that the country hosts, adding that Ankara must however respect human rights and the rule of law.
Ursula von der Leyen said following a meeting with President Recep Tayyip Erdogan in Ankara on Tuesday that Europe was committed to the continuity of such funding, but that rights issues had absolute priority and were "non-negotiable".
Turkey hosts some 4 million refugees, mostly Syrian, and has repeatedly accused the EU of not honoring promises under a 2016 deal under which it was to curb migrant flows to Europe in exchange for financial aid.
"The Commission will soon make a (funding) proposal," von der Leyen told a news conference alongside European Council President Charles Michel.
But Turkey must respect the rule of law and adhere to rulings by the European Court of Human Rights, and its withdrawal from the Istanbul Convention, aimed at protecting women's rights, had not send the right signal, she added.
The EU and the United States have also criticized a move endorsed by Erdogan's allies to shut down Turkey's third biggest party, the pro-Kurdish Peoples' Democratic Party (HDP).
In a sign of improving ties after months of tensions, EU leaders agreed last month to providing more money for refugees, as well as beginning work on deeper trade - though they warned of sanctions if Ankara restarted energy exploration in disputed waters.
Turkey is in dispute with EU members Greece and Cyprus over energy resources and jurisdiction in the eastern Mediterranean, and tensions flared in August when both Turkish and Greek navy frigates escorted vessels exploring for hydrocarbons there.
Michel said the bloc, which backs Athens, supported the resumption of talks with Ankara over the decades-old dispute.
Turkey is an EU candidate country, and last month the EU also opened the door to begin modernizing a customs union to allow unhindered bilateral flows of goods and services.
Erdogan has downplayed EU membership in recent years as the bloc has ramped up criticism of Ankara's foreign policy and rights record, and dangled the threat of EU sanctions.
Michel said that, if de-escalation continued, the EU would cooperate with Ankara on improving economic ties, supporting refugees and increasing mobility.
"Our engagement will be progressive, proportional and reversible and we hope Turkey will seize this window of opportunity," he said.
