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. Mottaki also criticized the UN Security Council for not responding to a letter he said Iran sent it in protest to the US detention. "The UN Security Council has refused to show appropriate action in cases like the diplomats' abductions although it has repeatedly interfered in cases not related to its duties under pressure from major powers," the Web site quoted Mottaki as saying. In another sign of strained relations Sunday, Iran's Foreign Ministry spokesman said Sunday that Teheran had no plans to meet with US officials on the sidelines of the upcoming conference on Iraq, Iran's state news agency, IRNA, reported. Mohammad Ali Hosseini's comments came a day after Iraq announced that ministers from its neighboring countries, the five permanent members of the Security Council and industrialized nations will hold a meeting in Egypt early next month to discuss the situation in Iraq. "Talks with the US is not on Iran's agenda," Hosseini said. The US has accused Iran of providing money and weapons to Shiite militias in Iraq, while Iran has argued that the presence of US troops is destabilizing the country. US officials have not commented on potential contact with Iran at the upcoming conference. Zebari on Saturday announced that the upcoming conference would be held in the Egyptian Red Sea resort of Sharm el-Sheik on May 3-4. But Hosseini claimed the date and location had not been decided and expressed Iran's desire to hold the conference in Baghdad. "Consultations are currently under way on (determining) the date and venue of the conference. No place has been fixed yet," he said. "Iran believes the meeting should be held in Baghdad." Iran also on Sunday confirmed that it refused to allow Iraqi Prime Minister Nouri al-Maliki's plane to fly through Iranian airspace, IRNA reported, quoting Hosseini. The spokesman said the dispute was a technical issue. "For all flights there is a need for authorization, for which formalities must have been done in advance," Hosseini was quoted as saying. Members of the delegation traveling with al-Maliki told The Associated Press early Sunday that the plane was diverted to Dubai, United Arab Emirates, where al-Maliki stayed in the airport for more than three hours while his government aircraft was refueled and a new flight plan was filed. Iraq has found itself in a tough diplomatic position since the US-led invasion in 2003, trying to maintain good relations with Teheran while not angering the Americans. Iraq's relations with Iran grew even more complicated last month when Teheran captured a British navy crew, holding it captive for nearly two weeks. Britain, which has more than 7,000 troops in southern Iraq as part of the US-led coalition, patrols the Iraqi coastline in the Gulf. Iran said the British crew was in its waters, but Britain denied the charge.