Thousands of British troops are ready to go into Afghanistan to monitor the cities of Kabul and Mazir-e-Sharif.
The Ministry of Defence said their mission will be to act as a stabilising force in allowing the UN to create a new government and to help to launch a full-scale humanitarian aid operation.
An MoD spokesman said that "several thousand" troops have been put on a two-day standby to enter Afghanistan after Northern Alliance fighters took control of Kabul yesterday.
But he stressed that no decision had yet been made to actually deploy the troops on the ground and there was no intention to deploy the forces in offensive operations against the Taliban.
"They are not an aggressive force. They will give the locals confidence and create the right conditions to allow the humanitarian agencies to do their work."
They will be aided by support units including RAF air support, helicopters, royal engineers, logistics experts and explosive disposal units. The troops will work separately from the 4,200 British soldiers already involved in the Afghanistan war.
PA