KABUL (AFP) - Thousands of Afghan and NATO troops are preparing for a major offensive in the southern province of Helmand, the hub of an insurgency that has raged for more than eight years, officials said Wednesday. The operation will be led by Afghan security forces as part of plans to hand over military and policing responsibility to the Kabul govt, said Afghan defence ministry spokesman Mohammad Zahir Azimi. It will be a joint Afghan army, police, US Marines and ISAF forces operation led by Afghans, Azimi told reporters. He did not give the exact date of the operation, although it is expected to be launched around the Marjah region of the troubled province within days. The offensive appears to mirror one in Helmands Garmser region last year, when US Marines led international and Afghan troops in clearing the area of Taliban, holding it and paving the way for development. We are going to go with the Afghan national security forces (to) clear, hold and build and deliver alternatives for all the Afghans, NATO spokesman Eric Tremblay told reporters. The operation will be one of the biggest since the war began, with thousands of troops focusing on a region considered a last bastion of Taliban control. In terms of strength there will be at least 1,000 Afghan national police, thousands of Afghan national army, and many thousands of ISAF troops, Tremblay said. Helmand, along with neighbouring Kandahar, is a hotspot of the brutal insurgency, which has paralysed much of the Western-funded post-Taliban reconstruction drive that followed the fall of the regime in 2001. The United States and NATO have 113,000 troops fighting the insurgents, with another 40,000 being deployed over coming months. Most of the new influx will be deployed to the south, taking the fight to the insurgents as the emphasis of the war switches to development. Insurgent violence has claimed the lives of 1,618 foreign soldiers and thousands of other mainly civilian lives since 2001, according to tallies from the website icasualties.org and agencies such as the United Nations.