A senior US State Department official on Tuesday played down tough criticism by Iraq's prime minister over the Haditha incident, saying "I wouldn't make too much out of" the remarks.
Prime Minister Nuri al-Maliki has strongly condemned the incident in the western Iraqi town of Haditha last November in which US Marines are accused of killing two dozen Iraqi civilians. The incident is under investigation.
The State Department's Iraq co-ordinator, James Jeffrey, said he believed US forces were well-respected in Iraq and Maliki's outburst was to be expected.
"It's a defence mechanism. ... I wouldn't make too much out of it," he said of Maliki's criticism. "There is a constant buzz in Iraq of what our troops did or didn't do," Jeffrey told a group of defence writers.
Last week, Maliki demanded the United States share files from the investigation of the Haditha killings, which he called a "terrible crime."
Jeffrey also said he did not believe the impact of the incident could be compared to the scandal over abuse at the Abu Ghraib prison near Baghdad, in which shocking pictures were published world-wide.
"I think this will not have the same impact (as Abu Ghraib) in terms of insurgents turning the population against us or turning opinion in the Arab world against us. But that is something that has to be evaluated every day," he added.
President George W. Bush has said he was troubled by news stories about the November 19 killings of men, women and children in Haditha, and a general at the Pentagon said the incident could complicate the job for the 130,000 US troops in Iraq.
Some US media have compared the Haditha shootings to the 1968 My Lai massacre in the Vietnam War, when US soldiers ran amok in the village. That incident eroded trust in the US forces both inside America and around the world.