BRUSSELS (Reuters) - Britain and the United States on Tuesday opposed a moratorium on the use of depleted uranium weapons, heightening political tensions within the 19-member NATO military alliance.

The two NATO allies shot down a request from Italy during a meeting of alliance officials in Brussels for a halt on DU arms until they had been deemed safe.

Controversy over the alliance's use of tank-busting shells coated with depleted uranium has erupted after at least seven Italian soldiers who served in the Balkans died of leukemia.

Many other Balkan veterans have fallen ill, with a range of symptoms from cancer to fatigue and hair loss, prompting calls for increased medical screening and alliance-wide research.

NATO officials maintained there was no proven link between the DU munitions used in the Balkans and cancer among Western peacekeepers, but agreed further studies should be carried out.

NATO ambassadors were due to meet formally Wednesday and would issue a statement, alliance diplomats said.

Belgian defense ministry spokesman Gerard Harveng told Reuters that 1,600 out of 12,000 troops who served in Balkan peacekeeping missions before the Kosovo crisis had complained of a lack of concentration, sleeping problems and headaches.

He said there had been nine cases of lung, skin, blood or brain cancer, five of whom had died.

He said it was not yet possible to determine any link between soldiers' illnesses and weapons used in the Balkans.

``That's why Belgium wants it on the NATO and EU table. (Our) minister wants to have a very big discussion, trying to find an answer and to determine if there is a danger or not,'' he said.

Nato Members Step Up Screening

Several other European states stepped up health checks on veterans and set up national inquiries into the potential risks of exposure to radioactive dust from DU missile explosions.

Bowing to overwhelming pressure, Britain announced it would test soldiers for possible health problems caused by DU arms, but insisted there was no evidence of a link.

``Some of the recent coverage will have caused some concerns among our people and we do recognize a need to reassure them,'' Defense Minister John Spellar told parliament.

He said studies of veterans from the Gulf War, 10 years ago, where similar DU ammunition was used, had thrown up no evidence of abnormally high cancer rates.

``DU will remain part of our arsenal for the foreseeable future,'' he said.

The French National Assembly defense committee announced it was widening a parliamentary probe into ``Gulf War syndrome'' to include the Balkans, coinciding with the discovery of a fifth case of leukemia in a Balkans veteran.

``It is not possible to ignore the emotion and concern about the health of our soldiers,'' said committee head Paul Quiles, calling on the United States to open its files on DU weapons.

A French journalist who covered the Gulf War and Bosnian conflict said she suspected DU-tipped arms caused intestinal, neurological and muscular problems she was suffering.

U.S. attack jets fired some 31,000 rounds of depleted uranium (DU) ammunition during NATO's 1999 campaign to end Serb repression of ethnic Albanians in Kosovo. About 10,000 rounds were also fired in neighboring Bosnia in 1994-95.

Calls For Research

The European Commission said it was setting up a working group of member state medical and scientific experts to report next month on the possible health risks from DU bombs.

``Ten years of conflict in the Balkans have created horrible environmental problems. We have to take care of our staff working there and also of (local) people,'' Commission President Romano Prodi told reporters during a trip to Sweden.

The World Health Organization has backed NATO's line that there is no proof linking DU weapons to leukemia, a potentially fatal blood cancer.

Experts from the Geneva-based WHO said studies in Kosovo hospitals had shown no rise in average levels of leukemia among the Serb province's largely Albanian civilian population.

Other scientists said it was unlikely that DU exposure caused poor health and leukemia among Balkan peacekeepers, but backed calls for more research into the possible health risks.

``The diagnosis of leukemia in many of these people is very soon after the alleged exposure. Whilst you can never say never in science, this does seems extraordinarily unlikely to be causal,'' Professor Eric Wright, an expert on radiation-induced leukemia at Britain's University of Dundee, told Reuters.

Defense experts urged NATO to agree alliance-wide research.

``There is no doubt in my mind -- there has to be an alliance-wide epidemiological survey,'' British military analyst Paul Beaver, spokesman for Jane's Weekly, told Reuters.

Russia, which has so far found no evidence of leukemia among its Balkan veterans, insisted an international inquiry was the only way to check claims of so-called ``Balkans Syndrome.''