United Nations Security Council resolution 631, adopted unanimously on 8 February 1989, after recalling resolutions 598 (1987) and 618 (1988) and having considered a report by the Secretary-General Javier Pérez de Cuéllar on the United Nations Iran–Iraq Military Observer Group, the Council decided:
(a) to call on both Iran and Iraq to implement Resolution 598;
(b) to renew the mandate of the United Nations Iran–Iraq Military Observer Group for another seven months and twenty-two days until 30 September 1989;
(c) to request the Secretary-General to report on the situation and the measures taken to implement Resolution 598 at the end of this period.