UNITED NATIONS - Iran is hosting a dinner Thursday night for UN Security Council members debating whether to impose added sanctions on the nation over its nuclear program.

Diplomats said Iranian Foreign Minister Manouchehr Mottaki invited the 15-nation council to dinner, and representatives of all member nations are expected to attend.

An American official called the dinner at Iran's UN Ambassador Mohammad Khazaee's residence "unusual" and said it is an indication of "the length to which the Iranians are going to make their case" against more sanctions.

The official said U.S. deputy ambassador Alejandro Wolff would attend in hopes the Iranians will show the council they will "play by the rules and meet their international obligations."