UNITED NATIONS - Iran has asked the United Nations for a comprehensive investigation of the conduct of US and other troops in Iraq and Afghanistan, saying they have failed to combat terrorism. The current method of combating terrorism, even if the claims of its proponents are accepted as true, has obviously failed, President Mahmoud Ahmadinejad said in a letter to Secretary-General Ban Ki-moon released by the Iranian Mission to the UN on Monday. He, therefore, called for an independent fact-finding team to launch a comprehensive investigation into the main intentions of NATOs military presence in Afghanistan and Iraq, the methods used, and the outcome of their presence and engagement, with the result to be presented to the General Assembly. Following September 11 (2001) attacks, and on the pretext of fighting against a number of terrorist operatives, more than a million people in our region have been victimized and a few more millions been displaced, two members of the United Nations have been occupied by NATO and US military forces, and a third country is susceptible to military aggressions, Ahmadinejad said. Nejad criticised what he described as US and NATO support for Abdolmalek Rigi, a terrorist and gang leader who used Afghanistan and Pakistan as safe havens for infiltrating Iran and carrying out a deadly attack. Rigi was recently arrested by Iranian commandoes. There is a concrete evidence on the involvement of intelligence and security services of at least three countries supporting his terrorist operations, the Iranian leader said. Rigi, identified by Irans government as the head of the rebel group Jundallah. , which carried out an October suicide bombing in Sistan-Baluchistan province that killed at least 40 people, including commanders of the countrys elite Revolutionary Guards Corps. UN spokesman Martin Nesirky said Ban hadnt received the Iranian letter and thus had no comment on Ahmadinejads request.