It is now expected that the first troops of a force of about 3,600 will leave on Monday.

They will serve in American, French and German sectors in Kosovo, following an earlier agreement with Nato.

Critics of the deployment have said it will cost too much, with Russia having too little say over how the troops were used.

K-For concerns

Two hundred Russian troops have been in Kosovo since mid-June when they occupied Pristina airport.

It is unclear exactly how the Russian troops will coordinate with Nato commanders, especially the American, German and French officers in whose areas the Russians will operate.

Albanians have protested at Russians replacing US troops

Reports suggest battalions of between 600 to 1,200 soldiers will be deployed in the three sectors as part of a unified command structure, but with Russia retaining complete military and political control of its own forces.

Seeking to allay doubts that K-For will work effectively, Nato Secretary-General Javier Solana said: "Russian and Nato troops work side by side in Bosnia, and I'm sure that they will do so again with equal success in Kosovo."

There also will be up to 750 Russians deployed at the Pristina airport, plus 16 Russians designated as liaison officers.

The Russians' logistics base will be in the vicinity of Kosovo Polje, to provide support for the Russian peacekeepers.

Some observers have warned that their arrival might cause new frictions with Albanians.