It is a work of art created by sculptor Hedva Ser, who is a UNESCO Goodwill Ambassador, the organisation says
The embassy said it considered that "holding a festive reception in this mourning times is not appropriate".
Islamist militants stormed a cafe and killed 20 hostages, including 17 foreigners. Nine of them were Italians, seven Japanese and one Indian.
Two policemen were also killed.
The radical Islamic State has reportedly claimed responsibility for the attack and released photos of the attackers who were killed in the commando operations.