NEW YORK – Iraqi Prime Minister Nouri al-Maliki said Sunday the shooting deaths of civilians – allegedly at the hands of Blackwater USA guards – and other violence involving the company pose “serious challenges to the sovereignty of Iraq” and cannot be accepted.

“The Iraqi government is responsible for its citizens and it cannot be accepted for a security company to carry out a killing,” he told The Associated Press, speaking in his New York hotel suite ahead of his appearance at the U.N. General Assembly.

Noting that Blackwater has been linked to at least seven incidents involving gunfire on Iraqi civilians, he added: “There are serious challenges to the sovereignty of Iraq.” In Arabic, he used the word “tajawiz” which can be translated either as “affronts” or “challenges.”

However, Maliki left open the possibility that Iraq and the United States would work toward a solution to the problem of Blackwater. “We have coordinated with the American side to establish a joint committee to ascertain the facts and hold accountable” those responsible, he said.

In the interview, Maliki defended his government and spoke up for the rights of Iraqis to manage their own affairs. He said that his country is making progress toward political reconciliation and that 2008 would be a year of political and economic progress and reconstruction for Iraq.

Speaking in a calm voice, al-Maliki was dismissive of some of the criticism directed at him by Washington politicians in recent months. Some members of Congress have said al-Maliki is not forceful enough in pressing for political reconciliation and achieving benchmarks meant to measure progress in the four-year U.S. intervention in Iraq.

Maliki said it is normal for any government to be criticized, but he feels certain that he has the backing in Washington he needs.

“What is important is that it did not come from the American administration or President Bush,” he said of his critics. “That it comes from other areas … for other reasons, is not a concern of mine. … It means nothing for me,” he said.

The Sept. 16 killing of at least 11 civilians near a square in central Baghdad has highlighted the practices of foreign security contractors whose aggressive protection of Western diplomats and other dignitaries has long angered Iraqis.

U.S.-Iraqi relations have been further strained by the U.S. detention of an Iranian on Thursday in northern Iraq.