Both countries accused US officials of spreading the accusations for political reasons - either to back Israel or to block progress on a deal between Washington and Pyongyang.

The two countries spoke out amid widespread speculation over a September 6 Israeli air incursion over Syria in which US officials have said Israeli warplanes struck a target.

Details of the incursion remain unclear, with Israel remaining silent. Syria has said no air strike took place and that warplanes violated its airspace and dropped munitions to lighten their load as they fled Syrian air defences.

Last week, a senior US non-proliferation official said Syria was believed to be approaching ``secret suppliers'' for nuclear technology and that North Korean personnel were in the country, raising theories that the Israelis were targeting a nuclear installation.

A Syrian Cabinet minister on Tuesday ridiculed the speculation.

``All this rubbish is not true. I don't know how their imagination has reached such creativity,'' Bouthaina Shaaban said of the reports of Syrian-North Korean nuclear cooperation.

She said the reports - including ones of a recent North Korean shipment to Syria - were ``all fabricated stories which have no value and truth.''