WASHINGTON - THE Bush administration appears set to offer Israel a powerful radar system that could greatly boost Israeli defences against enemy ballistic missiles while tying them directly into a growing United States missile shield.

President George W. Bush is expected to discuss the matter during a visit to Israel starting on Wednesday to mark the 60th anniversary of the Jewish state amid mounting US concern over perceived threats from Iran, people familiar with the matter said.

This is 'probably the No. 2 issue' on Mr Bush's agenda for the visit, second only to the Middle East peace process, said Representative Mark Kirk, an Illinois Republican who has spearheaded calls in Congress for tighter US missile-defence ties with Israel.

Mr Richard Lehner, a spokesman for the Pentagon's Missile Defense Agency, which is developing the multibillion-dollar layered shield, said questions about a new radar system for Israel were a 'policy issue' outside the agency's purview.

Mr Riki Ellison, a prominent missile-defence advocate with close ties to the Pentagon and companies involved in building the hardware, said he understood giving Israel the missile-tracking system was 'on the table right now'. The system Mr Bush may offer is known as a forward-based X-band radar. Transportable by air, it uses high-powered pulsed beams for extremely high-resolution tracking of objects in space such as a missile that could be tipped with a chemical, germ or nuclear warhead.

Built by Raytheon, the system has been described by US officials as capable of tracking an object the size of a baseball from about 4,700km away.

It would let Israel's Arrow missile defences engage a Shahab-3 ballistic missile about halfway through what would be its 11-minute flight to Israel from Iran, or six times sooner than Israel's 'Green Pine' radar is currently capable of doing, Mr Kirk said in a telephone interview on Friday. -- REUTERS