The US military has confirmed that its top commander in Iraq Lt Gen Ricardo Sanchez is to be replaced.
Gen Sanchez was praised by top officials in Washington
Officials say the move is part of a normal rotation after 13 months on duty and has nothing to do with the Iraqi prisoner abuse scandal.
Last week, Gen Sanchez said he took a personal responsibility for the abuse by soldiers at Abu Ghraib jail.
Separately, the Pentagon has suspended Brig Gen Janis Karpinski who was in charge of the prison near Baghdad.
A spokesman for Defence Secretary Donald Rumsfeld dismissed suggestions that Gen Sanchez's departure was linked to the abuse scandal.
"This is just wrong," Larry Di Rita said.
He said both Mr Rumsfeld and Joint Chiefs chairman Gen Richard Myers were "very impressed with the work Gen Sanchez performed" since he took command in Iraq in May last year.
Members of Karpinski's brigade have been accused of abuse
President George W Bush earlier also praised Gen Sanchez for doing "a fabulous job".
A Pentagon official told the BBC that the general had "done everything right" over the scandal of US soldiers abusing Iraqi prisoners in their custody.
But Gen Sanchez has faced criticism from some quarters over the scandal and, indeed, over his handling of the entire mission in Iraq, the BBC's Nick Childs at the Pentagon says.
Our correspondent says the three-star general is likely to be replaced by a more senior four-star officer, possibly the US army number two, the vice-chief of staff, Gen George Casey.
The Pentagon is actually revamping its whole command structure in the country as it prepares for the transfer of Iraqi sovereignty on 30 June, he adds.
Gen Karpinski was suspended from her duties as a commander of the 800th Military Police Brigade, which guarded prisoners at Abu Ghraib, army spokeswoman Pamela Hart said.
The officer - who was formally admonished by Gen Sanchez on 17 January - was "temporarily assigned to the US Army Reserve Readiness Command", US Army Reserve spokesman Steve Stromvall told BBC News Online.
However, US army officials say the measure should not should not be seen as punishment, but a temporary reassignment of duties, pending the outcome of the investigation into the abuse scandal.
In an interview with the Washington Post newspaper, Gen Karpinski insisted she had done nothing wrong and vowed to fight any action taken against her.
"I'm angry because it just seems consistent with the rest of this unfairness. This is such a gross miscarriage of justice," she was quoted as saying.
Members of her 800th Military Police Brigade were photographed and videoed abusing prisoners, sparking widespread outrage.
A report by Maj Gen Antonio Taguba into mistreatment at Abu Ghraib said Gen Karpinski and other officers paid too little attention to day-to-day operations at Abu Ghraib and did not take strong enough action against soldiers who violated procedures.
In her defence, Gen Karpinski argued that US military intelligence, not military police, controlled the cell blocks where the abuse took place.