"The government of Syria has informed me that it cannot provide me with numbers and timetables for any future withdrawal," Annan said.
"The report was compiled to monitor compliance with a UN Security Council resolution calling for the withdrawal of all foreign troops from Lebanon, where Syria has around 14,000 troops on the ground.
"The requirements on the various parties set out in resolution 1559 have not been met," said the report, obtained by AFP.
"The governments of both Lebanon and Syria have told me that the Syrian forces present in Lebanon ... are there at the invitation of Lebanon and that their presence is therefore by mutual agreement," the report said.