Migrants carry their belongings as they leave the Tae Kwon Do stadium at the southern suburb of Faliro in Athens, Greece, December 16, 2015. REUTERS/Alkis Konstantinidis

BRUSSELS (Reuters) - The European Union has seen little evidence that Turkey has managed to reduce departures of migrants for Greek islands in the two weeks since it signed an agreement to do so, an EU document showed on Thursday.

The report by the Luxembourg government, in its current capacity as president of EU ministerial councils, said about 4,000 people a day arrived from Turkey since the accord on Nov. 29, a “slight reduction” from the 5,000-6,000 seen earlier in that month. But this was not necessarily due to Turkish action.

“This decrease may, however, also be attributed to other factors,” said the report, seen by Reuters and sent to EU leaders ahead of a summit on Thursday in Brussels at which they will discuss efforts to stem the migration crisis.

A separate report on the functioning of the EU-Turkey action plan agreed with Prime Minister Ahmet Davutoglu in Brussels has concluded that migrant arrivals from Turkey were “practically unchanged” in the two weeks after the signing from the two weeks preceding it, an EU official said.

EU border agency Frontex has said arrivals in Greece in all of November were 108,000, roughly half the figure for October, largely because weather conditions had deteriorated. The agency said about 5,000 crossed in the last week of November.

Davutoglu met German Chancellor Angela Merkel and some other leaders before the main summit on Thursday to discuss a possible scheme to bring Syrian refugees directly from Turkey to Europe.

But many EU leaders have stressed that any such move depends on seeing evidence that Turkey is working to prevent people smugglers putting people to sea to reach Europe. That is also true of disbursement of the 3 billion euros ($3.3 billion) they pledged to Ankara on Nov. 29 and other concessions, such as easing visa rules for Turks coming to the EU.