"When the capital resists, the invaders can no longer advance and have to retreat," Sahhaf quoted the president as saying in a speech which claimed God was on the side of the Iraqis.

The speech, the latest in a series of calls for Iraqis to fight in recent days, also said they were determined to defeat the forces which have massed "at the doorstep of our capital," the speech said.

"Fight day and night, hit them without respite," said Saddam, whose recent non-appearance on state television has sparked speculation as to his whereabouts.

Saddam, who called Tuesday for jihad, or holy war, against the invaders, said "victory was assured in advance," according to Sahhaf.

"We believe in God and we count on him for a victory which he has promised to believers, and that is our right."

Baghdad has dismissed US suggestions that Saddam is no longer in effective control of the country he has ruled since 1979, or that he may have been killed in the thousands of coalition air strikes since the war began on March

He has been shown on television chairing meetings of his inner circle, but it is unknown when that footage was recorded.

He was last shown Thursday chairing an official meeting and vowing that victory against the advancing US-British forces was certain.

His defiant remarks came as coalition troops said they had entered Baghdad's outer rim and almost captured Saddam International Airport, some 20 miles (12 kilometres) from the centre of the capital.

"The Republican Guard, as well as the troops of our brave and heroic army, are Baghdad's virtual fortifications," Saddam was quoted as saying in his pep speech.

"You know your army's and your Republican Guard's strength when given the opportunity to kill the enemy," he added.

A spokesman at the US Central Command in Qatar said Friday that 2,500 Iraqi troops are reported to have surrendered to US Marines who clashed with Republican Guard units as they advanced north on Baghdad from the town of Al-Kut.

WAR.WIRE