US Secretary of State Hillary Clinton on Thursday urged Southeast Asian nations to help keep up pressure on Iran and end a diplomatic stalemate over talks on its suspect nuclear program.The United States viewed regional body ASEAN "as a partner in the broad international effort to prevent Iran from acquiring nuclear weapons", Clinton told a meeting of East Asian nations in Cambodia, according to the text of a speech released to the media."The best way to achieve the diplomatic solution we all seek is for the international community to stay united and to keep up the pressure that has brought Iran back to the negotiating table," she said.World powers have been pushing Tehran to abandon its enrichment of uranium, accusing the Islamic republic of trying to develop a nuclear weapon. Iran denies the accusations saying its nuclear programme is for civilian use only.So far, Iran and the P5+1 group of powers -- the five permanent UN Security Council members plus Germany -- have failed to reconcile their views on the nuclear issue.Two days of high-level talks in Moscow last month produced no progress and were followed by a meeting of experts in Istanbul in early July aimed at avoiding a total breakdown of diplomacy, which also concluded with no results."If we ease the pressure or waver in our resolve, Iran will have less incentive to negotiate in good faith or to take the necessary steps to address the international community's concerns about its nuclear programme," Clinton warned.A sweeping US and EU international oil embargo against Iran came into place on July 1.Numerous countries initially voiced concern about the US law. China and India were among the most outspoken, protesting that their energy-hungry economies should not be beholden to US domestic law.Just days before it came into force Washington exempted China and Singapore from sanctions over purchases of oil from Iran, saying major economies were united in pressuring Tehran.But the United States did not grant exemptions to smaller-scale importers such as Pakistan, meaning that its banks could face punishment if they handle transactions for Iranian oil.