Iraq's foreign minister says the United States must give a "clear timeline" for a U.S. troop withdrawal as part of a long-term security pact.
Hoshyar Zebari said Sunday that negotiators are very close to an agreement that includes such a timeline. U.S. officials say the talks have made progress, but they have not agreed to withdrawal dates.
U.S. officials have said the timing of troop pullouts should be determined by security conditions in Iraq.
A series of bombings killed at least 13 people in Iraq on Sunday.
In one of the deadliest attacks, gunmen and a suicide bomber attacked U.S. soldiers who arrived at the site of a roadside bombing, in the Tarmiyah region north of Baghdad. Four Iraqis and a U.S. soldier were killed.
At least four bombs went off around Baghdad, killing five people.
Elsewhere, Iraqi officials say a suicide bomber blew up a vehicle outside an Iraqi Kurdish security office in Khanaqin, northeast of Baghdad. They say the attack in Diyala province killed three people.
The U.S. military says insurgents in Diyala blew up a truck after exiting the vehicle, killing two people. It is not clear if that blast was the same as the one reported in Khanaqin.
In other developments, the U.S. military says Iraqi and U.S. troops discovered bombs hidden in a village school in Diyala on Saturday. It says the troops carried out controlled detonations and called in an air strike to destroy the remaining explosives.
The U.S. military said insurgents rigged the school with explosives to kill children.
The military also says coalition forces detained 10 al-Qaida in Iraq terrorists in central and northern Iraq on Saturday and Sunday.
Some information for this report was provided by AFP, AP and Reuters.