The United States says it is disappointed by Serbia's acquittal of two former policemen accused of involvement in the 1999 slaying of three Albanian-American brothers.
U.S. State Department spokeswoman Victoria Nuland said justice in the case remained a "high priority" in bilateral relations with Serbia.
In a retrial, Serbia's war crimes court on ruled on May 10 that there was not enough evidence to criminally convict the two Serbs for handing over Illy, Mehmet and Agron Bytyqi to a Serbian police unit that subsequently shot and killed them.
The retrial was held after Serbia's Appeals Court overturned an initial acquittal.
The three came to Kosovo from New York in 1999 to fight with the ethnic Albanian rebels against Serbia's rule.
Their bodies were discovered in a mass grave in 2001.
Prosecutors said they would appeal the new verdict.
With reporting by dpa