N.Y. State Law § 59-L
The governor of New York state, upon application by the United Nations, is authorized, to execute in duplicate, in the name of the state and under its great seal, a deed or release of the state ceding jurisdiction, to such extent and on such conditions as he may deem proper, of any land in the state acquired by the United Nations. Jurisdiction may be ceded directly to the United Nations or to the United States of America for the use and benefit of the United Nations. The application shall describe the land by metes and bounds and have endorsed thereon or annexed thereto the certificate of the attorney-general of this state that the United Nations is in possession of such land under full and complete title. The jurisdiction hereby authorized to be ceded shall continue with respect to such land as long as such land shall remain the property of the United Nations and be used exclusively for the purpose of establishing and maintaining thereon headquarters for offices and for places of assembly for carrying on the functions of the United Nations, and no longer.
N.Y. State § 59-L