ROME, May 13 (Xinhuanet) -- Italian Justice Minister Roberto Castelli has asked the United States government for collaboration in a judicial inquiry into the "friendly fire" killing of an Italian agent in Iraq, local media reported on Friday.

    Castelli spoke by telephone to his opposite number in Washington, Alberto Gonzales, on Thursday, requesting full cooperation with the investigation currently being carried out by Rome prosecutors, sources in Rome said.

    According to another report that US Under Secretary of State Nicholas Burns said on Friday the United States was willing to listen to any Italian queries on the "friendly fire" .

    During a visit to Rome on Friday, Burns told reporters that "from a military viewpoint" the US probe was officially over, noting that it had been carried out "thoroughly."

    But he made a point of saying that Washington was "politically open" to hearing any possible queries the Italian government may have.

    Intelligence officer Nicola Calipari was killed on March 4 whenUS troops manning a temporary roadblock opened fire on the car carrying him, another agent and a released hostage to Baghdad airport.

    A joint investigation by Italian and US military experts failedto reach a shared conclusion, with the American members clearing the soldiers of all responsibility and the Italians blaming the USorganization of the roadblock.

    A separate inquiry was launched by Rome prosecutors, who earlier this month inspected Calipari's car and are now believed to be studying forensic evidence.

    Both the United States and Italy have repeatedly stressed that the episode has not and will not call into question the long-standing ties based on shared values, between the two countries. Enditem