Goods arriving at Pakistan's ports destined for land-locked Afghanistan can again be transported across the country duty-free, the government has said.

The practice, known as transit trade, was always controversial as many products were smuggled back across the Afghan border for sale in Pakistan.

The terrorist attacks in the US on 11 September prompted the Pakistan government to abandon the agreement.

Now, after promises from the Afghan government to crack down on smuggling, the trade is to resume despite evidence the administration has little control over many regions along the border.

Transit trade will be allowed from Port Qasim and Karachi port to Afghanistan.

Imposing authority

The Afghan government has said it will "use all means" to reduce smuggling back into Pakistan, a practice that leading Pakistani author Ahmed Rashid described as the largest source of income for the ousted Taleban government.

But the Afghan administration could have difficulty controlling the movement of goods back across the border.

Afghan warlords continue to rule much of the countryside, taking taxes meant for Kabul, despite the best efforts of the government to impose its own authority.

Afghan customs officials say of the estimated $6m custom duties collected across the country each month, only $200,000 reaches the capital.

The rest is thought to end up in the pockets of Afghan warlords.

Meanwhile, the Afghan government is asking the international community for billions of dollars of aid to start rebuilding a country that has been devastated by 20 years of war.