Updated

Two U.S. F-35 fighter jets have arrived in NATO member Estonia to take part in NATO drills as the aircraft see their first operational deployment in continental Europe.

The planes with stealth technology to avoid detection by radar landed Tuesday at the Amari air base from the Royal Air Force base in Britain.

Air Marshal Stuart Evans of NATO's Allied Air Command said the F-35s will be "the fundamentals" in the military alliance's capabilities to defend the air sovereignty of its members.

The planes are part of the Pentagon's most expensive weapons program, estimated to cost around $400 billion.

Earlier this month, the U.S. Air Force deployed a fleet of F-35s, its newest and most powerful fighters, to Britain to reassure U.S. allies in the face of Russian aggression.