Russian 'reset' faces test as meetings loom on Iran, Syria President Obama's Russian "reset" will face another big test Monday, as he and his diplomats meet with their Moscow counterparts in two different cities on two of the trickiest foreign policy challenges of his administration -- Syria and Iran. In the Mexican city of Los Cabos, Obama is expected to meet with Russian President Vladimir Putin on the sidelines of the G-20 summit and have the chance to press Putin over the worsening situation in Syria. In Moscow the same day, negotiators from the U.S. will join diplomats from Russia and other countries to meet with Iran over its nuclear program. Efforts to stanch the violence in Syria and check Iran's nuclear program have hit serious roadblocks in recent weeks, and Russia is considered critical to untangling both messes. Yet the minimal progress has drawn renewed criticism of U.S. policy toward Moscow, albeit criticism that falls on the upswing of the presidential campaign season. As Secretary of State Hillary Clinton exchanged accusations this past week with Russia over its alleged support for Syrian leader Bashar Assad, Obama's Republican opponent Mitt Romney released a terse statement declaring that the U.S. approach to Russian relations had "clearly failed." Romney cited Russia's support for Assad as well as its alleged protection of Iran from international sanctions. Russia, though, is still seen by some as key to resolving these standoffs. Russia has gone along with U.N. Security Council efforts to tighten some penalties against Iran over its nuclear program, though it has blocked the harshest punishments. The U.S. remains under pressure to tighten the screws on Iran this week, with or without robust Russian backing. Dozens of U.S. senators from both sides of the aisle penned a letter to the president Friday urging Obama to stand tough against Iran in the upcoming talks. With new sanctions expected to take effect at the end of June, the lawmakers pressed the president to hold to them unless Iran truly reverses its position on nuclear program transparency. The senators backed the proposal floated at the last round of talks in Baghdad to compel Iran to halt uranium enrichment above 5 percent and export all uranium currently enriched above that level. Iran, though, bristled at that proposal in May. Dan Gillerman, former Israeli ambassador to the United Nations, said the U.S. needs to do more to convince the Iranians that military action is a real possibility. "The Iranians are using those talks to lull the world, put it to sleep and play the clock," he said Sunday on Fox News. Meanwhile, Obama faces an equally challenging task in trying to bring Russia back around on Syria. The White House tried to soften the blow of Clinton's accusation days before the G-20 meeting that Russia was equipping the Syrian government with attack helicopters that could be used against civilians. The United States has refused to arm anti-Assad rebels, in part to avoid a proxy fight in which Iran and Russia and others arm one side and the U.S. and Sunni Arab states arm the other. The administration continues to defend its policy toward Russia. "The reset with Russia was based on the belief that we could cooperate with them on areas of common interest, understanding that we saw some differences," White House Deputy National Security Adviser Ben Rhodes said Friday.