Taking his first faltering steps since his left leg was blown off by a landmine, Sergeant Muneer Ahmad is grim proof that the Afghan army is paying a heavy price in its war against the Taliban and struggling to care for its wounded.

Ahmad, 23, trod on a mine while fighting in the southern province of Kandahar six months ago as Afghan forces assume control of the anti-insurgent campaign after 12 years of well-funded US-led NATO operations.

With the NATO mission now shrinking rapidly, the future of Afghanistan rests with its national army and police, but rocketing casualty rates point to weaknesses in first-aid and a lack of long-term treatment.

US officials said that at the height of last year's "fighting season" more than 400 army and police were being killed in action every month, while the Afghan government does not release figures -- to avoid damaging public morale.

"I was very happy being a soldier," Ahmad told AFP as he struggled with his new prosthetic limb at an International Committee of the Red Cross (ICRC) orthopaedic centre in Gulbahar, 45 miles (75 kilometres) north of Kabul.

"I have heard no news of any compensation or pension. I was not receiving any treatment at all, so my family brought me here. The army didn't do anything."

Ahmad is still receiving his 12,000 Afghani ($215) monthly salary but doesn't know who will pay for any follow-up medical treatment and doubts whether the army will find him a desk job.

"It is a good feeling to be moving again," he said, sweating slightly as he gripped a handrail and took cautious side-steps. "It is only my second day. It is difficult."

Leg torn to shreds

Ahmad was in charge of an army checkpoint in the flashpoint district of Panjwayi when his left leg was torn to shreds below the knee.

"A civilian had been slightly injured by an explosion," Ahmad recalled.

"He came back, wanting a witness letter explaining how he had been hurt, so I took a few steps away to write it, and the mine exploded under me."

Ahmad was taken by car to the nearest military hospital and then flown, two days later, by a small Afghan plane to Kabul to be operated on.

In some ways, he was lucky.

There have been many accounts of Afghan soldiers bleeding to death from even minor battle wounds while waiting for air evacuation by the skeletal Afghan airforce or the declining number of US helicopters.

"I lost several friends in Kandahar," Ahmad said. "We were stronger than the Taliban, but they planted a lot of mines."

Like all amputees treated by the ICRC, Ahmad is being taught to walk again by former patients who have also lost limbs.

"Every day we have soldiers and police who come in, very severely wounded. We do receive a lot," said Alberto Cairo, the Italian head of ICRC's rehabilitation programme, which has centres in Gulbahar, Kabul and five other cities.

"The military hospitals ask us if we are ready to take their patients, and we always say yes.

"Sometimes they are brought in by military vehicles, but soldiers receive the same treatment as everyone else."

Last year, the ICRC registered 1,500 new patients who were direct victims of war in Afghanistan.

There are fears that the toll of wounded soldiers and police will rise further this year, with Taliban militants likely to target presidential elections in April and as NATO combat troops complete their withdrawal by December.

Long legacy of war

General Joseph Dunford, NATO's top commander in Afghanistan, has repeatedly warned that high casualty rates threaten the sustainability of the 350,000-strong Afghan security forces.

But General Mohammed Zahir Azimi, spokesman for the defence ministry, dismissed suggestions that poor medical care left many Afghan army and police feeling abandoned on the frontlines.

"We are coping well with this situation of wounded soldiers, and have enough trained medical staff in every unit. Of course, we are trying to increase capacity," he told AFP.

"The decline in US helicopters has had an effect on transporting the wounded, but with the arrival of two C-130s (large transport planes) we have been able to compensate to a good extent."

A NATO spokesman said that the Afghan air force had transported 1,540 battlefield casualties last year -- up from only 392 in 2012.

At the orthopaedic centre in Gulbahar, the long legacy of war is clear as Sergeant Ahmad learns to master his new leg alongside civilian victims of landmines and discarded ordinance.

Annifar is in to have her artificial leg adjusted, 27 years after she stepped on a Soviet-era mine.

Marzai, 24, tells of how she is now an ICRC trainer after losing a leg 12 years ago when a left-over shell exploded in her village.

"I tell new amputees that they are not alone, that they can have a good, full life," said Marzai.

For Ahmad, it is only the ICRC rehabilitation programme and his family's support that provide a ray of hope.

"I'd like to be useful, to work," he said. "I have come here to find out whether that might be possible."