British forces in Afghanistan will be provided with whatever resources they need, the prime minister has said.
Most British soldiers are based in Helmand province
Addressing military personnel on the fifth anniversary of operations in the country, Tony Blair pledged "every support and every protection".
He said this included providing more armoured vehicles and more helicopters.
Mr Blair praised the courage displayed during a "very tough" operation and acknowledged it was still "lawless" in the south where most troops were based.
The commander of British forces in Afghanistan, Brig Ed Butler, responded to the prime minister's offer of more resources by requesting helicopters.
He stressed that they had always been a "priority".
Brig Butler said if there were more helicopters "clearly we could generate a higher tempo - not just in offensive operations, but also to crack on with the reconstruction and development".
He added: "Clearly helicopters can't be grown overnight and nor can some of the other machinery, so there is a prioritisation that will have to be taken."
Meanwhile Kim Howells, the Foreign Office minister with responsibility for Afghanistan, stressed troops were fighting a "fierce battle" and were in the country for "a long haul".
He said that while British commanders felt they had all of the equipment they needed, they would like more support from some other Nato countries which were not "punching their weight".
In September alone, seven soldiers died in Afghanistan as a result of hostile action and 14 died when a RAF Nimrod crashed after a suspected technical fault.
With 40 British soldiers killed since September 2001, and high casualties in the past three months, Mr Blair was asked in the interview on the British Forces TV and Radio why troops were in the country as part of a Nato mission.
He said it was "frustrating" that some people did not recall the circumstances of the original deployment.
"It came about as a result of 11 September, as a result of the need to drive the Taleban and al-Qaeda out of Afghanistan," he said.
"If we let Afghanistan be used again as a training ground for the export of terrorism, it turns up on our streets - it harms British citizens."
He also said the government was expected to announce "in the next few weeks" details of "the package we provide for our troops when they're abroad fighting" but did not elaborate.
"Let me just make one thing clear: if the commanders on the ground want more equipment, armoured vehicles for example, more helicopters, that will be provided," he said.
"Whatever package they want we will do, and it's not surprising incidentally that as a mission proceeds so you may make adjustments as to what is necessary, what's not necessary."
Mr Blair went on to address recent criticism over the lack of dedicated military hospital facilities in the UK.
NATO FORCE IN AFGHANISTAN
31,000 troops now on ground in Afghanistan, including 10,000 coalition troops moved under Nato command
37 nations contributing
8,000 US-led troops continue training and counter-terrorism separate from Nato force
*Contribution figures may differ from exact numbers on the ground
He said when troops were injured on the battlefield, they were transferred to NHS services because "the specialist care for some of the injuries has to be of the top quality".
British troops are mainly based in southern province of Helmand, in a situation described by Mr Blair as "very, very tough".
He praised the troops' efforts, saying they had been "truly courageous" in fighting the Taleban and that their morale was high.
The prime minister's comments came as it emerged a Nato soldier had been killed in an attack on a patrol in the southern province of Kandahar. Nato did not reveal the soldier's identity or nationality.
Combat armour delay
Conservative MP Mark Lancaster, a member of the Defence Select Committee, is a Territorial Army reservist who was called up to serve as a Royal Engineer for a two-month spell in Afghanistan.
He said new combat body armour had not been given to all soldiers, despite claims in July it would be made available in the autumn.
Nato has taken charge of the country's eastern provinces, which have been under the control of US forces since the Taleban were ousted five years ago.
The alliance's International Security Assistance Force already commands troops in the north, west and south of Afghanistan, as well as Kabul.
It means that some 12,000 US soldiers have now come under the command of the British, led by Lt Gen David Richards.