South Korean defense officials are playing down a newspaper report saying North Korea is preparing to conduct a third nuclear test.Chosun Ilbo reported Thursday that U.S. spy satellites have detected increased activity at the North’s main Punggye-ri nuclear test site in the northeastern province of Hamgyong, citing an unidentified South Korean government source.But officials in the South’s defense ministry says such movements are constantly being detected at the site. One official says the movements could be due to maintenance.Pyongyang carried out its first nuclear test at the Hamgyong site in 2006, and the second last year, shortly after withdrawing from the six-nation disarmament talks aimed at ending the North’s nuclear program.The North has recently expressed its willingness to return to the negotiations.Chosun Ilbo says North Korea is using the possibility of another test to bolster its negotiating position with South Korea, while also boosting its military capability as leader Kim Jong Il prepares his youngest son, Kim Jong Un, to assume power – Voanews