While he did not completely dismiss the plan, worked out by Lord Owen and the veteran US diplomat Cyrus Vance, Mr Clinton none the less made it plain that in present circumstances it was unlikely to get his backing.
The President also suggested that any peace proposal should not be pushed through until directly supported by Boris Yeltsin, the Russian President.
The administration remains under intense pressure, meanwhile, to make clear exactly how it does intend to assist the peace process. Mr Clinton said he and and his security advisers needed 'a few days longer' to consider the options and to 'come up with what our policy is going to be'.
Mr Clinton is reported to have moved away from considering direct military intervention in favour of increased diplomatic activity.
The President said there was a particular danger that the deal could work 'to the immediate and to the long-term disadvantage' of Bosnian Muslims if its provisions were not fully respected by the other parties and if it was unenforceable from the outside.
His statement confirmed fears raised this week by Lord Owen that his plan, which would divide Bosnia into 10 autonomous areas under weak central government, was in danger of being smothered at birth by Mr Clinton.
Bosnia's Foreign Minister, Haris Silajdzic, in Washington yesterday to urge the administration not to back the deal, said the international community should move instead to impound all heavy weapons now in Bosnian territory. If the Serbs resisted, he said, Nato should 'bomb them'.
While Mr Clinton appeared to solicit some direct contribution to the debate from President Yeltsin, the Russian Foreign Ministry seemed yesterday to voice support for the Vance-Owen plan which, a spokesman in Moscow said, 'needs additional support'.
The immense difficulties of forging an agreement among all the parties was demonstrated last night when Bosnian Serbs toughened their position on the Vance- Owen map, demanding more territory, particularly in the north of Bosnia near the Serbia border.
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