WASHINGTON, Feb 18: US Defence Secretary Donald Rumsfeld on Thursday declared funding to complete a feasibility study for a nuclear earth-penetrating weapon a "sensible" response to rogue states that are moving sensitive facilities underground.

Congress cut off funding for the study last year but the administration is requesting 8.5 million dollars for next year to resume it and says it will need an extra 14 million dollars to complete it in 2007.

Called Robust Nuclear Earth-Penetrator, the study would examine whether a nuclear weapon can be designed to bore through concrete or rock and then detonate. Mr Rumsfeld said countries can now "dig holes through rock twice the height of a basketball net and the full length of a basketball court" in a single day with equipment that is widely available. -AFP