WASHINGTON (AFP) - Washington approved the US$3.3 billion (S$4.6 billion) sale of anti-ballistic missiles to Japan on Tuesday (Aug 27), following close behind a series of new ballistic missile tests by North Korea that could threaten the United States 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.

The sale came as North Korea expands its offensive missile capabilities, having proven over the past two years the ability to launch medium- and long-range ballistic missiles, potentially nuclear-tipped, that could hit both Japan and the US.

This month, Pyongyang has carried out seven tests of new short-range ballistic missiles, at least one of which flew far enough to reach Japan.

The Pentagon also approved new arms sales to Hungary, South Korea, Lithuania and Denmark, together worth another US$943 million.

Hungary will buy 180 AIM-120C-7 advanced medium-range air-to-air missiles, also made by Raytheon, the large defence contractor.

Denmark will buy low frequency sonar systems and sonobuoys from Lockheed Martin, Lithuania will obtain 500 Joint Light Tactical Vehicles, and South Korea will buy 31 MK 54 lightweight torpedoes, designed to be launched from P-8 Poseidon submarine-hunting aircraft.