The possibility of sending more UK troops to Afghanistan is being considered "as a matter of urgency", the defence secretary has said.
PM Tony Blair says UK troops in Afghanistan are "vital"
Des Browne said he had received advice on additional deployments and that he was discussing it with chiefs of staff.
The decision would be announced to the House of Commons as soon as possible, Mr Browne added.
The news comes a day after a UK soldier became the sixth in a month to die on duty in Afghanistan's Helmand province.
Private Damien Raymond Jackson, 19, from Tyne and Wear, died after being shot near the town of Sangin.
The soldier, from 3 Para Battle Group, was described as a "fine, upstanding, South Shields lad" by his father, Daniel.
The UK currently has 4,000 troops in Afghanistan, most of them in Helmand.
The number had been expected to peak briefly at 5,700 before dropping to about 4,500 as engineering staff began to withdraw.
Brigadier Ed Butler, who is in overall command of the UK troops in Afghanistan, had told the BBC two days ago that he had asked for extra resources, saying: "I've put in requests, which are being considered back in London as we speak, to take account for the change in circumstances."
Speaking in the Commons on Thursday, Mr Browne said Brig Butler's request was for extra engineering resources.
A Ministry of Defence spokesman said that the latest request from military commanders on the ground was for a "significant" increase in resources, but he would not confirm whether this would mean significant numbers of extra troops.
He denied that Mr Browne's announcement, possibly within days, was in response to a worsening situation on the ground, or to the deaths of six British soldiers in recent weeks.
The MoD spokesman said "the security environment has been tough, but we always knew it could be tough".
The UK troops in Afghanistan are part of a three-year Nato task force charged with helping the Afghan government to stamp its authority on the region.
Prime Minister Tony Blair said on Wednesday that the mission of UK troops in Afghanistan was vital for the security of the UK and the wider world.
He said British troops were doing "the most extraordinary and heroic job", which was important for the security of the wider-world and vital "to our security here in this country".