Britain said on Tuesday it had agreed to a NATO request to send a 600-strong reserve battalion to bolster an alliance peacekeeping force in Kosovo.

Kosovo's ethnic Albanian majority declared independence from Serbia on Feb. 17 in a move that had Western backing but was rejected by Serbia and its ally Russia.

The decision stoked tensions with the ethnic Serb minority in northern Kosovo that erupted into riots last month.

"We are well prepared to meet NATO's request and I have agreed to deploy our Operational Reserve Force battalion until June 30, 2008," Defence Secretary Des Browne said in a written statement to parliament.

"The deployment will demonstrate our commitment to the security of the region and will provide NATO with extra flexibility in maintaining peace and stability for all communities within Kosovo," he said.

The troops will spend about a month in Kosovo, from late May until the end of June, a Ministry of Defence spokesman said.

But they will be there during what is likely to be a tense period following a Serbian election on May 11 and around the time Kosovo's new constitution comes into force on June 15.

That is when the United Nations mission that has run the former Serbian province since 1999 is due to hand over its remaining powers to Kosovo's ethnic Albanian leaders and its European Union-led overseers.

UNCERTAINTIES

Questions remain over how the transition will proceed, after Russia blocked the adoption of a U.N. Security Council resolution endorsing the EU takeover and a U.N. plan for independence.

The British troops are from the 2nd Battalion, The Rifles, a light infantry unit based in Northern Ireland. They have been on standby to go to Kosovo since January.

They will supplement some 16,000 NATO-led peacekeepers already in Kosovo.

Kosovo suffered its worst violence since independence last month when Serb riots in the ethnically divided town of Mitrovica killed a Ukrainian police officer serving with the U.N. and left dozens of U.N. police and NATO soldiers injured.

About 120,000 Serbs live in the territory among 2 million ethnic Albanians, almost half of them in a northern strip backing onto Serbia, with Mitrovica as its centre.

The troop deployment has revived concerns in Britain that the country's armed forces are overstretched.

Britain said this month it would delay pulling up to 1,500 troops out of Iraq due to recent unrest in the southern city of Basra, keeping the force there at about 4,000.

Britain also has some 7,800 troops in Afghanistan.

Asked in parliament on Monday where Britain would find the transport aircraft needed to fly the troops to Kosovo, Armed Forces Minister Bob Ainsworth said Britain had made contingency plans and had moved equipment to Kosovo months ago.

Serbia lost control of Kosovo in June 1999 when NATO bombs drove out Serb forces to halt the killing and ethnic cleansing of Albanians in a two-year counter-insurgency war.

February's declaration of independence by Kosovo has been recognised by more than 30 countries, including the United States and most of the 27 EU member states.