After months of tough negotiations, Security Council powers said on Tuesday they were set to vote on a resolution that would impose a fourth round of UN sanctions on Iran because of its nuclear program. Mexico's UN Ambassador Claude Heller, current president of the 15-nation Security Council, told reporters it was due to meet for the vote at 1400 GMT on Wednesday, after broad agreement was reached on who would be targeted in Iran. US Defense Secretary Robert Gates said the expected passage of the resolution would provide a springboard for individual countries to take their own tougher measures against Tehran for refusing to halt uranium enrichment. Iran, however, warned its close trading partner Russia against joining Western nations in backing new punitive measures against the Islamic Republic. Western diplomats expect 12 of the Council members, including all the five that hold vetoes, to vote for the resolution. Turkey, Brazil and Lebanon are not expected to support it. Western diplomats said on condition of anonymity there were currently one individual and 41 entities, including a bank, blacklisted in the draft resolution. Meanwhile, Iran's President Mahmoud Ahmadinejad admonished Russia at a news conference in Istanbul, where he was attending a summit along with Russian Prime Minister Vladimir Putin, to take care “not to be on the side of the enemies of the Iranian people.” Putin said the sanctions should not be excessive. “We will have an opportunity to discuss these problems if my Iranian colleague will have such a need,” he said, adding there there should be no obstacles to the “development of Iran's peaceful nuclear energy.”