Prince Charles has paid tribute to Lieutenant Colonel Rupert Thorneloe, the most senior British officer killed in Afghanistan.

The prince, who is colonel-in-chief of Lt Col Thorneloe’s regiment, the Welsh Guards, said the news of his death was “completely heartbreaking”.

Lt Col Thorneloe, the commanding officer of the 1st Battalion Welsh Guards, was killed by a roadside bomb near Lashkar Gah in Helmand province, southern Afghanistan, on Wednesday along with 18-year-old Trooper Joshua Hammond, of 2nd Royal Tank Regiment.

Prince Charles, who knew the officer, paid tribute to him during a visit to Cornwall yesterday.

He said he had been “mortified” when he heard of the deaths.

“Having been colonel-in-chief of the Welsh Guards for the last 34 years, as you can imagine it is a wonderful family regiment and having been involved for those 34 years I’ve seen sons and grandsons go through the regiment.

“As you can imagine, the shock and horror that has affected the whole of the regiment family was quite dramatic.

“I was horrified to say the least about both deaths, Trooper Hammond as well.

“Having been to visit the Welsh Guards at Aldershot before they left to go to Afghanistan, having met the families and having met Col Rupert's wife, my heart is very much with them.

“It’s completely heartbreaking. The whole battalion is suffering.

“To lose a commanding officer who was such an inspiring person is an awful tragedy.

“It just goes to show the troops out there are meeting daily horrors.

“We owe them a huge debt of gratitude for their service.” Meanwhile, the defence secretary said that British forces in Afghanistan were “better equipped than they have ever been”.

Bob Ainsworth, speaking in Exeter, Devon, ahead of a military parade, said when asked if the vehicle Lt Col Thorneloe was travelling in was suitable: “If you ask anybody in Afghanistan they will tell you our forces there are better equipped then they've ever been.

“There’s been a fantastic improvement in the last couple of years, both in personal equipment and vehicles as well.

“We’re bringing in as many new vehicles out there as we can.”

Mr Ainsworth said bringing in more helicopters would not reduce the risk on the ground: “We can’t conduct the kind of operations we need to conduct in Afghanistan from the air. Of course helicopters are needed — we’re moving the Merlin helicopter across from Iraq — but ask the guys doing the job, they can’t conduct the operation in great big massive vehicles all the time, they need a range of vehicles.

“They need manoeuvrability, they need to be able to see what’s going on and they need to be able to get off the beaten track.

“But they equally need to get in among the people and to walk around and there’s always going to be risk.

“Ask anybody, even those who have been injured and they will tell you the risk can never be removed.

“There’s a long way to go and if we’re impatient about how we proceed in Afghanistan we will achieve nothing.

“But I believe progress is being made.”