The European Union's foreign policy chief has used a visit to Ankara to call on EU states to work closely with international partners such as Turkey to stop foreign fighters from traveling to the Middle East to join radical Islamist militants.
Federica Mogherini met with officials in the Turkish capital on December 8 to press for closer cooperation in the fight against Islamic State (IS) militants and urge Turkey not to undermine EU sanctions against Russia.
"We discussed the situation of foreign fighters. It is one of our common interests we have to face -- having good coordination and good strategy to stop the flow on both [sides]," Mogherini said at a news briefing.
Mogherini was accompanied to Turkey by the EU Enlargement Negotiations Commissioner Johannes Hahn and Humanitarian Aid Commissioner Christos Stylianides.
Mogherini held talks with Turkish Foreign Minister Mevlut Cavusoglu, Turkish President Recip Tayyip Erdogan, and Prime Minister Ahmet Davutoglu.
She called for a solution to the Syrian crisis "at the root" and voiced support for the mission of the UN's envoy to Syria Staffan de Mistura who is due to hold talks in Turkey with the leaders of rebels fighting President Bashar al-Assad.
Turkey has been a key transit point for Europeans traveling to Syria to fight with IS militants or other groups.
Reuters news agency quoted an EU official as saying the bloc wants Turkey to help identify foreign fighters.
But Turkey argues European governments should be doing more to stop would-be fighters traveling to the region.
Ankara also says it has made huge sacrifices in accommodating thousands of Syrian refugees.
The EU is due to announce an increase in EU aid to help Turkey cope with an influx of refugees from Syria and Iraq.
Negotiations over Turkish membership of the EU have been going on since 2005.
But political obstacles, notably over the divided island of Cyprus, and resistance to Turkish EU membership from some member countries, have slowed progress.
Enlargement Negotiations Commissioner Hahn said December 8 that one or more chapters could open in Turkish-EU accession talks in the future and that "things are moving in the right direction."
But he also said reforms are necessary by Turkey -- especially in the area of rule of law and the protection of fundamental human rights.
Hahn said: "We welcome recent moves and signals from member states and therefore.... I am hopeful that it might be possible to open one or the other chapter in the next presidency."
Ankara has not joined Western sanctions against Russia over its role in Ukraine's crisis, and the EU is urging it to do so, or at least not to take advantage of the situation by exporting affected products to Russia.
During Russian President Vladimir Putin's visit to Turkey a week ago, Moscow announced it was scrapping the South Stream gas pipeline project and named Turkey as its preferred partner for an alternative pipeline route.
Russia and Turkey are major trading partners, with Russia providing the bulk of Turkey's natural gas supplies.