Her Majesty's Royal Marines have forced US troops to surrender only days into a training exercise where the Brits eliminated the entire unit, according to The Telegraph.

The Royal Marines supposedly "dominated" US troops in the California-based training session, where they used new tactics aimed at achieving mobility.

The British forces will now use these new tactics across all deployments after the success of the training exercise. There will be a particular emphasis on bringing this new structure to the Baltic and Oman where the UK has garrisons of Royal Marines.

US forces asked for a reset halfway into the training session. The training only lasted five days, during which the US suffered extensive mock casualties.

The UK forces managed to eliminate every single American asset during this period.

A British Lieutenant Colonel said that "throughout this deployment, our focus has been on integrating game-changing capabilities from across the commando force to deliver disproportionate effect in the face of a free-thinking peer adversary."

The exercise ended when the British troops secured 65 percent of the possible territory, having started at 20 percent.