"We covered 80% of his burns on the chest and abdomen with skin from his back," Imad Najad, a plastic surgeon treating the 12-year-old boy at the hospital in Kuwait City told AP after Sunday's surgery.

Kuwaiti Health Ministry spokesman Ahmed al-Shatti said the operation "went even better than expected", and said the boy was "smiling and responding well".

Ali was the only survivor after a US missile destroyed his house in Baghdad, killing his entire family.

But after amputating the boy's arms above the elbow, Iraqi doctors feared he would die of blood poisoning as they lacked the facilities to give him the specialist treatment he needed.

After an international appeal for help, Ali was airlifted to Kuwait where he is being treated at the Saud A Albabtain Centre for Burns and Plastic Surgery.

'In better spirits'

"The operation was very successful. He's now resting," Dr Najad said after the surgery, which replaced a temporary graft earlier this month.

"He is in much better spirits than before," Dr Najad added.

But the surgeon said that Ali still remained in the intensive care unit and would need more skin grafting surgery, which could be performed in 10 days to a fortnight.

Meanwhile, medical staff at the hospital said they continued to search for the best possible artificial limbs to help the boy regain as normal a life as possible.

The Kuwaiti Government - which volunteered to take Ali for treatment - has already been approached by several charities offering to pay for the boy's treatment and prostheses.