Istanbul, Turkey - US special envoy Karen Hughes met the head of the Orthodox Church, Patriarch Bartholomew I, at the end of a three-country regional tour, sources from her delegation said.
No statement was issued after the meeting as Hughes, undersecretary of state for public diplomacy, left for Washington at the end of a tour that also took her to Egypt and Saudi Arabia.
The aim of the trip was to polish the image, battered by the war in Iraq, of the United States in the Muslim world.
While in Istanbul, Hughes also met representatives of the Muslim, Orthodox, Armenian, Jewish and Syriac communities.
One issue likely to have come up in her talks with Bartholomew I was the fate of the Greek Orthodox seminary on the island of Heybeliada (Halki in Greek), off Istanbul, that was closed down by Turkey in 1971.
Washington, along with Greece, wants Turkey to re-open the school.
The Turkish government has said on several occasions that it is looking into ways to allow the school to re-open.
Improving rights for non-Muslim communities is a key requirement Turkey needs to fulfill in order to become a member of the European Union, with which it is scheduled to begin accession talks on Monday.
Turkey, 99 percent Muslim, is also home to some 40,000 Armenians, 35,000 Jews, 20,000 Syriacs and 4,000 Orthodox Greeks, who live mainly in Istanbul, the country's biggest city.