A convoy of US vehicles from Kuwait arrives Monday in Basra, 550km south of Baghdad. The first additional US troops, who will take part in a major new security plan in Baghdad, arrived in Baghdad, General George Casey, the US commander in Iraq, said (Reuters photo by Atef Hassan)

BAGHDAD (AP) — The US ambassador and top American commander in Iraq are set to leave their jobs with the country’s security arguably no better than when they arrived, and they cautioned Monday against expecting significant success in quelling the violence soon.

RIYADH (Reuters) — Iran asked Saudi Arabia to help ease tensions between the Islamic republic and the United States as Washington held out the possibility of “engagement” with Tehran if it changed tack in Iraq.