US soldier killed in southern Iraq

One American soldier was killed in Iraq on Sunday, as the new US defence secretary arrived and expressed \"tremendous concern\" over Iran-supplied weapons Washington says are being used to attack its troops. \"A US service member was killed Sunday in southern Iraq,\" said a brief statement by the US military in Iraq that gave no other details. The death is the third so far this month, after June was the deadliest month in three years for US forces in Iraq, with 14 soldiers killed. Sunday\'s death raises the full number of American military fatalities in Iraq since the 2003 US-led invasion to 4,472, according to an AFP count based on the website www.icasualties.org. US Defence Secretary Leon Panetta arrived from Afghanistan on an unannounced visit to inform Iraqi leaders they must decide soon whether they want American troops to stay in the country beyond the scheduled pullout at the end of the year. About 46,000 US soldiers remain in Iraq, down from a high of 170,000 since the invasion which toppled dictator Saddam Hussein. The top US military officer said on Thursday that Iran is stepping up its support for Shiite militants in Iraq, supplying them with more sophisticated weapons. Admiral Mike Mullen said Iran had made a decision to curtail its support for Shiite factions in 2008 but has now increased its activity in Iraq, sending in lethal arms that were being used against American forces. Asked about the increase in attacks against US forces by Shiite militants backed by Iran, Panetta expressed \"tremendous concern,\" and called on Iraq to do more to \"go after those extremists that are making use of these weapons\" supplied by Tehran. \"If we\'re all gonna be partners, they have a responsibility to protect against that kind of attack. It\'s in the interest of Iraq to provide for their own security,\" he said. Iran has denied US accusations of smuggling weapons to insurgents to its two neighbours, Iraq and Afghanistan. Panetta is the latest senior US official to arrive in Baghdad to convince Iraqi leaders on the importance of a contingent of American soldiers remaining behind. US diplomatic sources in Baghdad say there has been no talk on the possible number that could remain.