The US and Iran say they will hold upcoming talks in Baghdad about improving Iraq's security - a historic political turnabout for the two countries with the most influence over Iraq's future. Expectations of progress remain low, however, with tough issues at stake and mutual suspicions running high. Even as it announced the talks Sunday, Iran lashed out at US Vice President Dick Cheney's weekend warnings about its nuclear program, saying it would retaliate if the US attacked it. Yet the two sides said they were setting aside such differences to focus on a narrow issue - Iraq's continued violence and sharp political deterioration. "The purpose is to try to make sure that the Iranians play a productive role in Iraq," said Gordon Johndroe, the White House's National Security Council spokesman. Cheney's spokeswoman, Lea Anne McBride, also confirmed the upcoming talks, saying the vice president supports the move as long as they focus solely on Iraq. Iran agreed to the talks "after consultation with Iraqi officials, in order to lessen the pain of the Iraqi people, support the Iraqi government and establish security and peace in Iraq," the state-run news agency, IRNA, quoted Foreign Ministry spokesman Mohammad Ali Hosseini as saying. Iraqi leaders have leaned on the Bush administration to try to cooperate with Iran in the interest of stabilizing their country. Likewise, some Mideast Arab allies of the US - increasingly distrustful of Iraq's Shi'ite-led government - have pushed for talks with Iran as a way to reduce sectarian tensions in the country and stop attacks against Sunnis. The decision to talk comes at a critical time of plunging US support for the war and growing pressure from Congress for Iraq's government to make some political progress, or lose US backing. Many critics say the US- and Iraqi-led security push and troop buildup is also struggling. In March, lower-level US and Iranian diplomats did hold rare, brief talks on the sidelines of a Baghdad gathering. At a follow-up conference a week ago in Egypt, there was a casual chat between the US ambassador to Iraq, Ryan Crocker, and Iran's deputy foreign minister, Abbas Araghchi. There had been speculation of a Cabinet-level meeting at that Egypt conference, but neither US Secretary of State Condoleezza Rice nor Iran's foreign minister wanted to make the initial move, passing up what would have been the first high-level, face-to-face talks since the US broke off relations with Teheran after the 1979 hostage crisis.