Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. NATO Says 30 Days Needed to Secure Marjah VOA News 18 February 2010 US Marines with NATO forces keeps vigil as Marines and Afghan National Army (ANA) soldiers setup a joint military base in north of Marjah, city of Helmand province, 18 Feb 2010 Photo: AP US Marines with NATO forces keep vigil as Marines and Afghan National Army (ANA) soldiers setup a joint military base in north of Marjah, city of Helmand province, 18 Feb 2010 A NATO commander in southern Afghanistan says allied troops will need 25 to 30 days to overcome what he called "stiff resistance" from Taliban fighters and secure Marjah. British Major General Nick Carter told reporters Thursday that the 15,000 Afghan and NATO troops in the offensive are moving carefully to try to avoid civilian casualties and roadside bombs. He said it could be three months before officials are able to determine if the offensive is successful. On Thursday, the governor of Afghanistan's Helmand visited Marjah for the first time, six days after the offensive began. Governor Gulab Mangal said a convoy of Afghan national police had arrived in Marjah. Afghan officials are planning to quickly deploy government workers and security forces to begin providing security, services and jobs. At least five NATO soldiers and at least 15 civilians have been killed since the start of the operation late Saturday. The number of reported Taliban deaths has risen to 40. Meanwhile, in northern Afghanistan Thursday, Afghan officials said a NATO air strike mistakenly killed seven Afghan police and wounded two others. A spokesman for the Afghan interior ministry said NATO forces came under Taliban attack and called in an airstrike, which mistakenly hit a nearby group of Afghan police. NATO forces later released a statement pledging to fully support a joint investigation with the Afghan government. Some information for this report was provided by AFP, AP and Reuters. .