Defence Minister Bob Ainsworth has said he is "busting a gut" to get more helicopters out to Afghanistan.
Mr Ainsworth also said the increasing toll of British casualties in Afghanistan - 19 this month alone - was not in vain and "huge progress" was being made.
Meanwhile, the 19th British serviceman to be killed in Afghanistan this month was named as Guardsman Christopher King, 20, from Birkenhead.
Colleagues said he was a "fearless soldier and ever-cheerful friend" while his parents described him as a "tremendous son". The soldier, from 1st Battalion Coldstream Guards, who was attached to 1st Battalion Welsh Guards, died in an explosion on Thursday morning while on patrol in the Nad e Ali district of central Helmand province.
Mr Ainsworth, speaking on a visit to HMS Monmouth, which is currently docked in Cardiff Bay, said: "We will never be entirely in a position where the full length of the Helmand valley, every single commander, has got every single vehicle they might want on every day."
He added: "It can't be done, but we've got to reach for that. Our military commanders don't plan operations and didn't plan Panther's Claw not knowing exactly what they've got in terms of capability. They knew how many helicopters were available for that operation."
He said there were "no contradictions" over whether there were enough helicopters in Afghanistan. "We are busting a gut to get more helicopters out there. There are eight Chinooks waiting to go out there. We have already massively increased our helicopter capability 60% in terms of air frames, we are driving people harder, getting them to work smarter. The Merlin fleet will be out there by December. I was all over it again myself yesterday to make sure it can't be done quicker.
"We've still got two Merlin that need new rotor blades and new night vision and we've got to give the crews training. There are people who think if we've got 100 helicopters we can put them in Afghanistan. They are not Ford Mondeos. They break. They have a massively complicated defence capability. They are operating in just about the worst environment in the world with dust, heat and height. They break and they're breaking all the time. Some are fixed in theatre and some come back here.
Mr Ainsworth said he was concerned the British public were starting to think deaths of British troops in Afghanistan were in vain. He said: "I'm worried there's an impression we are not moving forward and these sacrifices are being made at a time when we are not making progress. We've made huge progress, there's real momentum in Afghanistan."
He said troops in the country had gained "a massive amount" of ground in Helmand province in recent months and were slowly clearing the area.
