Tony Blair today called for an urgent United Nations presence in Kabul to fill the "power vacuum" left by the fleeing Taliban.
The Prime Minister insisted that the successor government to the crumbling Taliban regime must be "broad based" and represent all the country's ethnic groupings.
He told reporters in Downing Street that the regime was now in "disarray and retreat" and called for a stepping up of the humanitarian aid effort.
However, Mr Blair also cautioned that the US-led coalition had yet to succeed in its objective of bringing to account Osama bin Laden and his al Qaida terrorist network and said that the military campaign must continue.
"Once the military strategy is vindicated, our forces know and I know that this is only setting the conditions in place for our objectives to be achieved," he said.
Mr Blair thanked British troops who aided the Northern Alliance advance, saying they had "acquitted themselves brilliantly".
Mr Blair emphasised the importance of maintaining order in Kabul now that the Taliban had left.
"I believe we can make real progress towards filling the power vacuum in Kabul but we need a UN presence as quickly as possible," he said.
The Prime Minister added that he believed the Northern Alliance, which is predominantly made up of Tajiks and Uzbeks, had accepted that there needed to be a broadly-based successor regime to the Taliban including representatives of the Pashtuns, the country's largest ethnic grouping.
"It has to include all the various groupings in Afghanistan and it must obviously include a Pashtun element," he said.
"I believe that is accepted by the Northern Alliance."
Mr Blair said that the coalition's task had been eased by the flight and disintegration of the Taliban forces.
"They are clearly in retreat and in some cases in a state of collapse but it is too early to say the objectives have been met," he said.
Mr Blair praised the leadership shown by US President George Bush and the role played in the military campaign by the British forces although he refused to be drawn on any further operations they may perform.Reuse content