Britain's foreign policy chief said Monday that Iran's nuclear program presents "the most immediate threat to the stability" of the Middle East, but that it had to be confronted only through diplomacy. He also urged a comprehensive Middle East peace agreement - what he called a "23-state solution." Speaking at a conference on nuclear energy in the Gulf held in United Arab Emirates capital Abu Dhabi, Foreign Secretary David Miliband said the choice for Iran was clear: "It can cooperate and halt its enrichment or continue on its current path toward the future of confrontation and isolation." But he also stressed that the international community was not aiming to bring down the Iranian regime, and appeared to rule out a last-resort military option. "The pressure we are applying to Iran, the sanctions we have supported in both the EU and the UN, are not an attempt at regime change," Miliband said. "And nor are they a precursor to military action. We are 100 percent committed to a diplomatic resolution of this dispute. We will work closely with the new US Administration on this issue." Miliband said that "a nuclear-armed Iran would present a decisive blow to those seeking peaceful solutions to the region's problems. The consequent nuclear arms race would be very dangerous. The acquisition of a nuclear weapon would strengthen Teheran's regional position, injecting its attempts to stoke up division and promote instability with much greater confidence." For diplomacy to work, he went on, the choice facing Iran needed to be made "more and more stark" - "combining increasingly tough sanctions with clear offers of reintegration" that would hopefully "veer the Iranian government off its current course." Miliband's comments came a few days after a report by the International Atomic Energy Agency said its investigation into Iran's nuclear program was "deadlocked." Britain, the US and many other Western countries accuse Iran of using its nuclear program as a cover for weapons development - a claim denied by Teheran. Iran rejected Miliband's comments, saying its enemy Israel was the greatest threat in the Middle East. "If an opinion survey is done in Britain, a majority of people will reaffirm that the Zionist regime, Israel, is the main threat to the region," said Iranian Foreign Ministry spokesman Hasan Qashqavi. The IAEA said in a report last week that Teheran's stonewalling meant the agency could not provide credible assurances about the nature of Iran's nuclear program. Turning to the Middle East peace process, Miliband declared that "the situation on the ground... leaves too many people insecure, in poverty and despair, [and] is rapidly undermining the political process." He noted that he recently visited Jenin in the West Bank and saw "a success story in terms of the Palestinian Security Force but met Palestinians who feel hopeless and humiliated. Their daily experience is of checkpoints, road blocks and harassment. "In Gaza it is worse," he said. "Restrictions on access for supplies through the border crossings have left its citizens short of food and medicine. While their leaders negotiate with the Israelis, settlement construction makes them fear they are being robbed of that which they are negotiating over. "There is a similar sense of insecurity on the Israeli side," Miliband went on. "They feel threatened and under siege. They tried withdrawal from Gaza and Lebanon, but were greeted with rocket fire. They supported democratic freedoms for the Palestinians, only to see an organization which vowed to destroy them gain the most votes. They fear Iran's intentions, not only in the development of its nuclear program, but in its support and weapons supplies to Hamas and Hizbullah. Therefore, he said, "Those who believe in peace, those who want to end this conflict through cooperation rather than confrontation, must act now to prevent a downward spiral, to stop the illegal settlement activity, the rocket attacks and the fragmentation of Palestinian politics and society, all of which are eroding the chances for peace and justice." His visit to the region last week, he added, left him convinced that "the only peace will be a comprehensive peace. A peace with an independent Palestinian state at its core, but underpinned by a broader peace between Israel and the whole Arab world. In other words, a 23-state solution - 22 members of the Arab League, plus Israel."