New Delhi, July 2 -- Self-flying fighter jets, uncrewed submarines and drones will be at the center of Britain's future military under a defense plan announced Tuesday that includes a 15 billion pound ($20 billion) spending boost.

Like other NATO countries, the U.K. is under pressure to increase defense spending to counter a more aggressive Russia and less reliable United States. But its Defense Investment Plan has been repeatedly delayed as military leaders and Treasury officials wrangled over the cost.

Prime Minister Keir Starmer said the plan reflects a world of conflicts transformed by technology and will keep Britain safe in "a more dangerous and volatile world."

"When the world is arming and aggression is rising, the best way to ...