Iranian Ambassador to Iraq Hassan Kazemi-Qomi (file photo) (epa)
January 29, 2007 -- U.S. President George W. Bush says he will respond "firmly" if Iran steps up "military action" in Iraq in a way that hurts U.S. troops or Iraqi civilians.
Bush made the remarks in an interview with National Public Radio today.
Washington charges that Iran is helping insurgents who target U.S. troops, a claim denied by Tehran.
Also today, Bush's chief spokesman, Tony Snow, said Iraq is free to seek closer ties with Iran, after Iran's ambassador to Iraq, Hassan Kazemi-Qomi, said Tehran wants to boost its military and economic role in Iraq.