According to The Jerusalem Post:
An agreement signed last year making the Vatican’s de facto recognition of a Palestinian state in 2012 official has come into effect, the Holy See said on Saturday.
The Vatican signed its first treaty with the “State of Palestine” last June when it called for moves to end the Israeli-Palestinian conflict and backed a two-state solution.
“… the Holy See and the State of Palestine have notified each other that the procedural requirements for (the accord’s) entry into force have been fulfilled, the Vatican said in a statement on Saturday.