Zahi Hawass says the chariot will leave Egypt on Wednesday accompanied by an Egyptian conservator.
The chariot was supposed to join the exhibition of King Tut's famous artifacts when the exhibit opened.
Initially the chariot was late due to the volcanic ash that suspended flights from Europe, but the reasons for the further delays were unclear.
The Tut exhibit features about 130 objects including more than 50 of his burial objects.
A blockbuster exhibition on the boy-king was first shown at the Metropolitan Museum of Art in 1979 and drew millions.