(Adds Greece denial, details of delay)
BEIRUT, Jan 21 (Reuters) - Syrian state television said a plane carrying Syria's delegation to international peace talks in Switzerland on Tuesday was "prevented from refuelling" after it landed at Athens airport.
The lengthy delay might force the cancellation of a planned meeting between Syrian Foreign Minister Walid al-Moualem - who was on the plane - and United Nations Secretary General Ban Ki-Moon, state TV said.
Greece's Foreign Ministry spokesman confirmed that the plane had been temporarily detained but had now been cleared for take-off, although Greek air traffic controllers said the plane was still in Athens.
Negotiations between President Bashar al-Assad and opposition figures to try and end a three-year conflict are due to start on Wednesday in Switzerland following several days of disarray as world powers bickered over who would attend.
"The delegation's plane landed at Athens international airport and was prevented from refuelling," Syrian television said, adding that all airspace permissions had previously been granted for the flight.
Greek Foreign Ministry spokesman Konstantinos Koutras told Reuters: "The issue has been settled, there was a small delay over formalities."
"Everything is OK, it has been cleared for take-off," he added, without giving details on the reason for the delay. (Reporting by Oliver Holmes in Beirut and Harry Papachristou in Athens; Editing by Gareth Jones)