By Sue Pleming and David Brunnstrom

BRUSSELS, Dec 7 (Reuters) - NATO ministers were set to pledge on Friday to keep their peace force in Kosovo at current strength as it heads towards independence and to make more troops available as necessary to deal with any violence.

Ethnic Albanian leaders of the breakaway Serbian province are expected to declare independence in the next couple of months after the failure of international mediation, potentially sparking new unrest in the Balkans.

A senior U.S. official said NATO ministers would announce at a meeting in Brussels on Friday that NATO's KFOR peace force, currently 16,000-strong, would remain at current levels "with full flexibility for the commanders".

Belgian Foreign Minister Karel De Gucht said after a dinner of NATO and EU foreign ministers on Thursday that all agreed that KFOR strength should be maintained.

He said NATO Secretary-General Jaap de Hoop Scheffer had said additional troops would be made available at short notice if needed. "Everybody agreed to that and nobody was putting into question their contribution to KFOR," he told a news briefing.

On Friday, NATO foreign ministers will be asked to confirm they will not lay down limits on how the KFOR can deal with violence as they did when riots in 2004 caught NATO off-guard.

Washington has wanted to ensure KFOR nations would not put "caveats", or limits on what duties their forces could perform.

A senior U.S. official said the announcement on Friday would mean "a far more capable force...you can put the forces where you need them".

"It means that NATO is prepared to fulfil its role looking into the future despite what is almost certain to be a change in the situation on the ground." he added.

MEDIATION FAILS

International mediators will report to the United Nations on Dec. 10 that efforts to reach a compromise between Pristina and Belgrade failed. Russia wants further mediation, but the West says the time to settle Kosovo's status has come.

Washington and the vast majority of European Union states are likely to recognise a declaration of independence by Kosovo, expected around late January, and a senior NATO envoy said no KFOR country had indicated a wish to pull troops out.

De Gucht said that while there was not complete agreement among EU states, they were agreed on the importance of maintaining a consensus.

Diplomats believe an explicit pledge by alliance nations that they will keep KFOR at full strength and not impose caveats -- such as banning their troops from riot control -- to be a crucial deterrent in the tense weeks ahead.

NATO commanders are confident KFOR is well resourced to deal with trouble and diplomats play down the prospects of violence.

But the West has been irked by aggressive rhetoric from Belgrade, and on Thursday the EU's mediator on Kosovo demanded that Serbia disown a comment made by an adviser to Prime Minister Vojislav Kostunica that "war is a legal tool".

"I do hope this statement was not authorised. I expect it to be retracted," Wolfgang Ischinger told reporters in London.

Kosovo has been administered by the United Nations since a 1999 NATO bombing campaign to halt ethnic cleansing by Serb forces of the 90 percent ethnic Albanian province, which Belgrade insists must remain under its sovereignty.

NATO foreign ministers are also set to state the Alliance's view that U.N. Security Council resolution 1244, adopted after that war, gives it a mandate to remain in Kosovo even after independence. (Writing by Mark John; Editing by Caroline Drees)

AlertNet news is provided by