The United Arab Emirates (UAE) has requested the purchase of a new US missile defence system developed by Lockheed Martin Corporation, a deal that could be worth $7 billion, if approved, two sources familiar with the discussions told Reuters on Wednesday.

Colonel Bill Lamb, who manages the US Missile Defense Agency's Terminal High Altitude Area Defense (THAAD) program, confirmed that an unidentified country had requested a sale of the sophisticated system and that the Pentagon was discussing it with lawmakers.

Lamb, who said the deal would be worth "close to" $7 billion, declined to identify the buyer or give other details.

Two sources familiar with the request, who asked not to be named, identified the potential buyer as the UAE. One said the deal could be formally announced in June or July.

Once the Pentagon's Defence Security Cooperation Agency notifies Congress about the proposed sale, lawmakers have 30 days to object, although such action is rare.

"As far as I know, everyone who's looked at it thinks it's a good idea," said one of the sources.

This same source noted that the defensive nature of the weapon system made it more palatable to US lawmakers than the sale of satellite-guided munitions to Saudi Arabia, which had provoked some criticism.

The Pentagon has spent $11 billion over the past 17 years to develop the new missile defence weapon, which is designed to defend troops, population centers and critical facilities against short- to medium-range ballistic missiles of a type that could be fired by Iran or North Korea.-Reuters