The US government has denied test-firing a submarine-launched ballistic missile capable of carrying nuclear warheads during a joint military exercise with Saudi Arabia.
A Western military official in Saudi Arabia, speaking anonymously because of the sensitivity of the issue, said a Trident missile was launched out in the kingdom yesterday.
But Lt Col Jonathan Withington, a US Defence Department spokesman, said there was no launch of Trident or any other missile during the exercise, which began last week.
The US has been strengthening missile defences in allied Arab nations in the Gulf to help counter any potential missile strike from Iran.
Like its nuclear work, Iran's missile programme is of top concern to Washington and Arab nations wary of Tehran's growing influence in the region.
The Western military official in the Saudi capital, Riyadh, said US Lt Gen Patrick O'Reilly, head of the Missile Defence Agency, attended the test launch, but a second defence official in the US said that while Lt Gen O'Reilly was in the region last week, he did not attend a missile launch.