WASHINGTON, April 11 (Xinhua) -- The United States remains ready to talk to Iran about improving security in Iraq, U.S. ambassador to Iraq Ryan Crocker said here Friday.

    Crocker denied speculation that the United States may resort to military strike against Iran because of their long and acute contradictions, including alleged Iran's involvement in insurgency in Iraq and disputed Iran's nuclear program.

    "No one is talking about a war with Iran," Crocker said.

    It has been an international concern when President George W. Bush and his top aides have warned time and again that the United States will not rule out a military option against Iran.

    The U.S. ambassador also urged Arab countries to make more effort to help Iraq counterbalance Iran's influence.

    Crocker told reporters that "If the Arabs are concerned about Iranian influence and encroachments in Iraq ... They need to be diplomatically involved there. They need to be economically involved. They need to be working on development issues."

    "They need to demonstrate to the Iraqis -- the people, not just the government -- that the Arabs care what happens there and want what happens there to be positive both for Iraq and for the region," he said.

    The United States, which accuses Iran of providing weapons and funds to the insurgents to fight against coalition forces in Iraq, has held with Iran three rounds of talks over Iraq's security issue but failed to reach any agreement.

    More than 4,000 U.S. soldiers have been killed since the war of Iraq broke out in March 2003. Iran denies U.S. accusations, saying "the U.S. just wanted to find excuses for its failed policies in Iraq" and it was the existence of U.S. forces made that war-torn country volatile.