In the most recent attack, a US soldier was killed in a roadside bomb attack near the town of Baquba, north of the capital Baghdad on Sunday.
Two other soldiers were wounded in the attack on their convoy which was hit by an explosive device, a US military spokesman said.
"One 4th Infantry Division soldier was killed and two were wounded when their vehicle hit an IED (improvised explosive device) at 0740 (0440 GMT) this morning," Lieutenant Colonel Bill MacDonald, a spokesman for the 4th Infantry Division based around Tikrit, told reporters.
Earlier, in Iraq's main northern city of Mosul, two US soldiers were killed by Iraqi resistance fighters while their vehicle was caught in traffic.
Witnesses said attackers slit the throats of the two soldiers in the centre of the town.
The US military has confirmed two soldiers from the US 101st Airborne Division, based in Mosul, had been killed but denied their throats had been cut.
The attacks on US troops came hours after the killing of an Iraqi police colonel in Mosul. Abd al-Salam Qanbar was shot by suspected resistance fighters on Saturday night.
With the latest deaths, 185 US soldiers have been killed in action since the US declared major combat in Iraq over on 1 May.