Iran's foreign minister warned Sunday that cooperation with Iraq could deteriorate if five Iranian diplomats detained by US troops in Iraq are not set free - a move that could further complicate relations between the neighboring countries. Foreign Minister Manouchehr Mottaki said Teheran is seriously pursuing the fate of the detained diplomats and urged Iraq to do the same, according to Iran's state broadcasting company's Web site. "In a note to Iraqi Foreign Minister Hoshyar Zebari and some other officials, I stressed that if their efforts do not yield results, it will undermine Iran's aid to Iraq," the state broadcasting company's Web site quoted Mottaki as saying. The United States detained five Iranians in the northern Iraqi city of Irbil in January and refused to release them or allow Iranian officials a chance to visit the men. The detentions have hindered relations between predominantly Shiite Muslim Iran and Shiite-led Iraq.