BEIJING, May 28 (Xinhua) -- Iran and the United States held ambassador-level talks in Baghdad on Monday, the first meeting since the two countries severed diplomatic ties in 1980.

    Iran and the United States had shared close ties before 1979, when Shah Mohammed Reza Pahlavi was in power in Iran.

    Relations between the two sides begun to deteriorate after the 1979 Islamic revolution in Iran, during which Iranian students seized the U.S. embassy in Tehran and took 90 hostages.

    The then U.S. President Jimmy Carter broke the diplomatic ties on April 7, 1980 following the embassy hostage crisis. Iran responded by calling the United States as its "arch enemy."

    During the Iran-Iraq war, the U.S. Navy destroyed several Iranian battleships and oil platforms, and in 1988 a U.S. warship also shot down an Iranian passenger plane over the gulf, killing all 290 people on board.

    When the eight-year-long war drew to an end in August 1988, Washington said on several occasions that it wished to restore high-level contacts with Tehran, an offer that was refused.

    The United States continued its policy of political isolation and economic sanctions against Iran during Bill Clinton's presidency, and the policy became even tougher when George W. Bush was elected to the White House in 2002.

    Bush accused Iran of being a member of the so-called "axis of evil," saying Iran was a staunch supporter of terrorism.

    In 2003, the United States criticized Iran over its nuclear enrichment program and threatened the use of force if efforts failed in bringing a peaceful solution to the nuclear crisis.

    In 2005, Iran's newly elected President Mahmoud Ahmadi Nejad said his country would not give up its nuclear program. His remarks triggered great tension in Washington, who later pushed UN Security Council to pass resolutions for economic sanctions against Iran.

    Since the outbreak of the Iraq war in 2003, the United States has been accusing Iran of supporting militant groups in Iraq, an accusation Tehran has resolutely denied.

    However, as the security situation worsens in Iraq and U.S. casualties increases there, the Bush administration realized that to solve the crisis in Iraq, neighboring countries including Iran must be get involved.

    Starting at the beginning of this year, Washington has stepped up efforts to make contact with Tehran. The Iranian side, while expressing a willingness to cooperate, also stands by its right to peacefully use nuclear power.