Washington, July 18 (IANS) US is building a missile defence radar station in Qatar, and construction was due to be completed this month, a media report said Tuesday.

The radar site is part of a system designed to defend US interests and allies against Iran's ballistic missiles, Xinhua quoted the Wall Street Journal as saying.

The base in Qatar is slated to house an AN/TPY-2 radar, supplementing two similar arrays already in place in Israel's Negev Desert and in central Turkey, the Journal said.

Together, the three radar sites form an arc that US officials say can detect missile launches from northern, western and southern Iran.

Those sites will enable US officials and allied militaries to track missiles launched from deep inside Iran.

The radars are linked to missile-interceptor batteries throughout the region and to US ships with high-altitude interceptor rockets.

The paper also said the Pentagon chose to place the new radar site in Qatar because it is home to the largest US military air base in the region, Al Udeid Air Base.

More than 8,000 troops are stationed there and at another US base in Qatar.