Israeli forces began taking control of the building and evicting people from it on Tuesday. The building is located near the Qalandia refugee camp.
"The Secretary-General is deeply concerned about this development, as it will deprive young people of the vocational training they have received," Guterres' spokesman Stéphane Dujarric said in a statement.
The training centre was established in 1952 and offers vocational training each year to around 340 Palestinians from the occupied West Bank.
As of January last year, Israel has banned the UN agency from operating on Israeli territory.
