Washington approved the $3.3 billion sale of anti-ballistic missiles to Japan on Tuesday, following close behind a series of new ballistic missile tests by North Korea that could threaten the U.S. ally.

Japan will buy up to 73 of the Raytheon-made SM-3 Block IIA missiles, which are designed to be fired by the ship-board Aegis system to intercept incoming ballistic missiles, the Pentagon said.