The US government has appealed against the dismissal of a case against five Blackwater security firm employees.

Vice President Joe Biden, who is in Iraq to discuss the political crisis in the country, told journalists a dismissal is not the same as an acquittal.

The case against the five Americans, who are suspected of murdering 17 Iraqi citizens in September 2007, was thrown out of court because the judge ruled their rights had been violated.

The decision caused outrage in Baghdad, and the Iraqi government threatened to start its own case against the men.

The main purpose of the vice president's visit is sort out a political crisis in the run up to the parliamentary elections in March. More than 500 Sunni candidates have been rejected because of alleged ties with Saddam Hussein’s banned Baath Party.

Vice President Biden said the elections have to be free and fair, but stressed that he would not be interfering with internal issues.

Photo: Vice President Joe Biden with Iraqi Prime Minister Maliki - EPA