Powell will make a brief stop in the Serbian capital on Wednesday en route from Turkey to Belgium to show US support for the country that was shaken last month by the assassination of Prime Minister Zoran Djindjic, the officials said.

"He wants to pay his respects and re-affirm our commitment to emerging democracies like Serbia," one official told AFP on condition of anonymity, adding that the new stop would not change the rest of Powell's itinerary.

After his talks in Ankara aimed at shoring up ties damaged by the Iraq crisis, Powell is due in Brussels for meetings with NATO and EU officials on Thursday to discuss post-war reconstruction efforts.

A formal announcement of the Belgrade stop was expected later Tuesday from deputy State Department spokesman Philip Reeker, the officials said.

Powell will be the highest-ranking US official and first secretary of state to visit Belgrade since the 1999 Kosovo conflict that eventually led to the downfall of former Yugoslav strongman Slobodan Milosevic.

Djindjic, who was slain on March 12, was instrumental in the movement to oust Milosevic and later turned him over to the International Criminal Tribunal for the former Yugoslavia (ICTY) where the he is now on trial for war crimes.

The Serbian Interior Ministry said Monday that Djindjic had been murdered by self-styled patriotic forces in Milosevic's name and there have been charges that the ex-leader's wife ordered the killing.

Milosevic's wife, Mirjana Markovic, who disappeared in 2000 just before her husband was ousted from power, has flatly denied the accusations.

SPACE.WIRE