In a dramatic show of strength by Theresa May, HMS Diamond, a Type 45 destroyer equipped with the latest anti-aircraft rockets, will set sail for Ukraine carrying up to 60 Special Boat Service and Royal Marine commandos.
The move is part of the biggest British military build-up on Russia's borders for decades, and comes after British PM told U.S. politicians that Britain and America should stand up to President Vladimir Putin.
HMS Diamond will lead a NATO task force and help protect British instructors involved in teaching infantry skills to thousands of Ukrainian troops.
The high-tech warship, which was launched in 2007 and entered service three years later, will carry Sea Viper missiles.
Travelling at nearly 3,000mph, the radar-guided warheads have a range of up to 70 miles (about 112 kilometers) and can destroy enemy jets and drones.