Disarray within the Taliban leadership could delay peace talks with the Afghan government for a few months, but up to 70 per cent of the militant group may ultimately be reconciled with Kabul, the top US commander in Afghanistan predicted on Thursday.

“I think it's going to take a good couple of months before we see them kind of back to any kind of peace negotiation,” US Army General John Campbell told a hearing of the Armed Services Committee in the US House of Representatives.

“I think reconciliation talks will continue, but it's going to take some time to bring the right people to the table to do that,” he said.

The Afghan Taliban attended a round of peace talks with the government in July, but later disavowed the negotiations after the disclosure that Mullah Omar, the elusive leader of the militant group, had died two years earlier in neighbouring Pakistan.

Mullah Mansour was chosen as the new Taliban leader, but some factions of the group opposed his selection and called for a new leadership vote. Mansour's message for Eidul-Azha discussed resurrecting peace talks with Kabul.

Campbell said he thought 60 per cent to 70 per cent of the Taliban's members would ultimately be open to reconciliation.

The general told lawmakers earlier this week that he favoured retaining a larger US military presence in Afghanistan next year than envisioned in current plans, which calls for an embassy-based force by the end of 2016.

Campbell also said the United States has about 9,800 troops in Afghanistan. Of that number, 1,300 were tied to day-to-day training and advising missions with only 500 of those were outside the capital Kabul, he said.

While declining to elaborate on his recommendations to President Barack Obama for next year, he told lawmakers a reduction in troop numbers to an embassy force would limit the ability to conduct train, advise and assist missions and eliminate counter-terror operations.

Campbell said Afghan security forces had a number of shortcomings, including its limited air support capability.

“Sir, if they had the A-29 this summer, it would have been a game changer in some locations,” Campbell said in response to a question from the committee. He added that the first five or six A-29 planes would not be received until the end of the year.