The tree, weighing nearly 5 tons, will be decorated with more than 2,500 gold and silver balls and more than 2,500 energy-efficient white and yellow lights, Italian news agency ANSA reported.
With help from a helicopter, the tree was cut down last week in Ukraine's southwestern region of Transcarpathia.
The tree is to be hoisted to its upright position beside the obelisk in St. Peter's Square Monday. A lighting ceremony, to be attended by a representative from the Ukrainian Orthodox Church, is scheduled for Dec. 16.
ANSA said it's considered an honor to donate a Christmas tree to the Vatican, and this marks the first time a former Soviet country has donated the tree since Pope John Paul II began the Vatican Christmas tree tradition in 1982.
European countries including Romania, Austria and the Czech Republic have donated trees in recent years.