The Hague: Lawyers representing Slobodan Milosevic have asked the UN war crimes tribunal to issue a subpoena to force former US president Bill Clinton to testify at his trial, documents showed on Tuesday.

"In his position as former president of the United States, Mr Clinton had a continuous role and unique knowledge of events relevant to the indictment," the lawyers said in a written request filed last week but only made public on Tuesday.

Lawyers Steven Kay and Gillian Higgins said his evidence was needed to make sure the trial was "informed and fair". They said Milosevic had written a personal letter to Clinton asking him to testify but had not received a response. They added the US embassy in The Hague had written to them last year explaining the opposition of the US government to the request.

Kosovo conflict

Milosevic, who has argued that he was a peacemaker in the 1999 Kosovo conflict and that the West committed war crimes, has also asked the court to subpoena retired American general Wesley Clark to appear as a witness in his defence.

Clark directed Nato's bombing of Kosovo in an 11-week campaign led by Clinton and British Prime Minister Tony Blair to halt Serbian repression in the region.

Judges decided last year not to call Blair and Gerhard Schroeder, German Chancellor at the time of the bombing, as witnesses.

Milosevic has been on trial for four years on charges of genocide, crimes against humanity and war crimes.

He has used up more than four fifths of the 150 days allotted for his defence, which suggests the case could be wrapped up in the next few months.