Turkey has denied that it is shifting its allegiances to favour the Middle East rather than the European Union.
PM Recep Tayyip Erdogan said Turkey was still committed to EU entry - though he accused some European countries of a "secret agenda" to keep it out.
On Wednesday the US defence secretary said Turkey might have been "pushed by some in Europe" away from the EU and closer to states like Iran.
Turkey this week voted against new UN sanctions on Iran.
Turkey's once-close alliance with Israel has also come under severe strain.
Their relations were already deteriorating before Israeli troops stormed a ship carrying aid to Gaza last month, killing nine Turks.
'We carry on'
But Mr Erdogan denied Turkey was turning away from Europe.
He said: "There are those within the European Union who are trying to slow down the negotiating process, those who want to prevent the process. They are trying to curb our enthusiasm.
"We are aware of their secret agenda, but we carry on [with reforms] nevertheless."
The issue of whether Turkey should join the EU strongly divides European governments.
It started formal membership talks in 2005, but has only been allowed to open 12 of the 35 chapters that candidate countries must complete.
Some, like Britain, firmly believe Turkey should be encouraged to modernise and westernise, and that welcoming a big Muslim country would strengthen Muslim moderates. The US has also supported this view.
But other countries, like Germany and France, fear Turkey could destabilise the EU, not least with mass migration, and think it should be offered no more than a "privileged partnership".