Around 20,000 Ukrainians are to be put through an intensive five-week course to help them prepare for combat.

His Majesty watched as the men - mostly civilians - stormed a mock trench.

"We're trying to get them to learn how to use the ground to their advantage," said Capt Freddie Bradshaw from 1 Irish Guards.

"We've got urban and trench complexes which they can use. They need to learn how to fight in a forest - a lot of Ukraine is forest.

"There's a huge amount of experience from the training teams here.

"We are trying to make them as lethal as possible in a short space of time - five weeks is a very condensed training package," he said.

At an undisclosed location in Wiltshire, the King told one of the senior officers: "You are amazing, I don't know how you do it.

"I am full of admiration," he added.

Afterwards, with the help of a translator, King Charles took time chatting to 20 of the Ukrainians.

Many of them left their civilian jobs to join the army - one was a mechanic, another a teacher.

One Ukrainian soldier told the BBC: "It's an amazing feeling to be in the presence of His Majesty.

"It's been the event that most light will shine upon my life.

Another one said: "He asked how training was going, and our health, and took an interest in the wellbeing of our families and wives.

"I feel light on my feet and I think it will sink in a few days later," he said.