Nabil Elaraby's comment followed talks with Palestinian President Mahmoud Abbas.
"It's time for Palestine to be member state at the U.N.," Elaraby told reporters. He noted that 100 nations have recognized Palestine as a state.
The Palestinians are campaigning for U.N. nonmember state status in the West Bank, Gaza and east Jerusalem, the territories Israel captured in the 1967 Mideast war.
The Palestinians insist they remain committed to negotiating the terms of Palestinian statehood with Israel.
Israel charges the Palestinians are trying to delegitimize it and bypass negotiations.