Impoverished North Korea has spent an estimated 700 million dollars this year on nuclear and missile tests, enough to solve its food shortage for at least two years; South Korean news reports said Monday. The figure includes the estimated 43 million dollar cost of test-firing five Scud and two Rodong missiles Saturday, according to unidentified government officials quoted by Chosun Ilbo newspaper. The latest tests, staged on the US Independence Day holiday, were seen as a show of defiance to Washington as it seeks tough enforcement of UN sanctions aimed at shutting down the communist state's nuclear and missile programmes. Officials quoted by media estimated it cost 300 million dollars to launch a long-range Taepodong-2 missile on April 5, and another 10 million to launch 10 short-range missiles in recent weeks. In addition, they estimated the May 25 underground nuclear test -- the country's second since 2006 -- cost between 300-400 million dollars.