By Kylie Morris BBC correspondent in Kabul

A senior United States defence official has said that no matter what happens elsewhere in the war on terror, his government will stay committed to Afghanistan.

Mr Feith said promised funds would reduce tension

At the same time, Under Secretary of Defence for Policy, Douglas Feith, said security in Afghanistan is primarily up to Afghans themselves.

Mr Feith delivered his assessment of the role of American military forces in Afghanistan, during a visit to the capital Kabul.

While he spoke of a continuing commitment, he also emphasised the importance of Afghans creating their own national army.

Mr Feith said he was reasonably confident the Afghan authorities would recognise that, but also expressed an understanding that people might be sceptical of new forces, given the history here of war.

New fears

Asked about fighting between warlords in regions of Afghanistan, Mr Feith said the US Defence Department was working directly with regional leaders.

Gulbuddin Hekmatyar: Emerging concerns

But he predicted that when the aid money that has been promised to the country materialises, then local frictions would be reduced.

He said Afghanistan's problems would be lessened if only the international community delivered on the money it has promised.

Mr Feith said the American focus remained on al-Qaeda and Taleban in Afghanistan, but added that if their tactics changed the Americans would adapt as required.

There are fears that the remnants of al-Qaeda and the Taleban may be reconstituting themselves in an alliance with fighters loyal to the former Mujahideen leader Gulbuddin Hekmatyar.