An Iranian proposal made public on Thursday offers wide-ranging talks with the West but is silent about its nuclear program, a mixed message that may undercut any push for further U.N. sanctions on Iran for now. Separately, an Iranian official ruled out any talks about Iran's uranium enrichment program, which the West suspects may be a cover for developing nuclear weapons but which Iran says is solely intended to produce electrical power. Russian Foreign Minister Sergei Lavrov said the Iranian proposal provided something to work with, and he ruled out the possibility of sanctions on Iran's lifeblood oil sector. Western powers are becoming frustrated by what they have called Tehran's "persistent defiance and point-blank refusal" to suspend uranium enrichment and its avoidance of negotiations as demanded by U.N. Security Council resolutions since 2006. Instead of directly addressing those demands, Iran handed world powers on Wednesday a five-page proposal -- first made public by a U.S. website -- that spoke generally of talks on political, security, international and economic issues. "The Islamic Republic of Iran voices its readiness to embark on comprehensive, all-encompassing and constructive negotiations aiming at acquiring a clear framework for cooperative relationships," said the proposal released by ProPublica (www.propublica.org), an independent, nonprofit newsroom that produces investigative journalism. The document's authenticity was confirmed by a diplomat briefed on the proposal. The United States said the proposal was "not really responsive to our greatest concern, which is obviously Iran's nuclear program." Among the issues Iran said it was willing to discuss was "putting into action real and fundamental programs toward complete disarmament and preventing development and proliferation of nuclear, chemical and microbial weapons." The proposal also held out the possibility of talks on "the root causes of terrorism," energy security, preventing another global financial crisis, solving the Israeli-Palestinian conflict and reforming the U.N. Security Council. "Tehran is prepared to have fair and substantive talks about various problems, including the guarantee of access by all countries to nuclear energy and preventing the proliferation of nuclear arms," Iranian state television quoted Ali Asghar Soltanieh, Iran's envoy to the U.N. nuclear watchdog, as saying. "But these talks do not include Tehran's nuclear program and legal activities in this connection." The United States, Russia, China, Britain, France and Germany are evaluating Iran's plan and their senior diplomats are to hold a conference call to discuss it on Friday. U.S. President Barack Obama has suggested Iran may face much harsher international sanctions, possibly targeting its imports of gasoline, if it does not accept good-faith negotiations by the end of September. But Russia, which has veto power in the U.N. Security Council, ruled out oil sanctions against the Islamic Republic. "Based on a brief review of the Iranian papers my impression is there is something there to use," Lavrov told reporters in Moscow. "The most important thing is Iran is ready for a comprehensive discussion of the situation, what positive role it can play in Iraq, Afghanistan and the region," he said.