WASHINGTON (AFP) NATOs withdrawal from Afghanistan will be gradual and not a brusque lights out next August, the commander of international forces there, US General David Petraeus, said Wednesday. Asked about an exit date, Petraeus told NPR radio the idea of some date out there is not unprecedented, mentioning past practice in Iraq. But the idea of an August date for a pullout is not a lights out moment, he added. For those who had another impression, Petraeus stress-ed: we just have to keep on explaining. On the Talibans inroads in Afghanistans north, Petraeus said: Its a process that has been ongoing for years. Yet when asked if NATO had dropped the ball on that account, Petraeus said that in the past they did not have means to carry out the kind of comprehensive counterinsurgency that was needed. Now, we can broadly say that we have the inputs right, he said. Its not a conventional battle. It is slow progress. You take steps forward but you also take steps backward, Petraeus told NPR. Meanwhile talking to a TV channel, the top NATO commander in Afghanistan said that progress in the war was slow in coming, sometimes as slow as watching grass grow or paint dry. Petraeus told ABC News that American and coalition troops are nevertheless making headway with hard fought gains against insurgents but that it remained tough going. Recounting his impressions from a battlefield tour, Petraeus said the fight was very difficult and sometimes - seeming to be as slow as, again, watching grass grow or paint dry. But nonetheless - progress. Asked where US-led forces had reversed the Talibans momentum, Petraeus said that coalition troops had seized the initiative in the centre of Helmand province in southern Afghanistan. I think theres no question that in Helmand Province, the six central districts of Helmand province - are a good bit more secure than they were even six months ago, he said in the television interview. He also insisted that coalition efforts in Marjah - the site of a major US-led offensive in February - were paying off, despite persistent violence and setbacks. A high school had opened in Marjah for the first time in six years, an interim police station was operating and drug dealers allied with insurgents no longer sold opium in the local market, he said. The insurgency could no longer rely on Marjah as its major command and control headquarters in the province, he said. In a separate interview with National Public Radio, Petraeus struck a similarly cautious tone, saying operations in the strategic Kandahar province would take time to bear fruit and the effort had to be Afghan-led. He said coalition forces were about to launch more nuanced operations around Kandahar to win back areas that were never cleared of insurgents, according to excerpts of the NPR interview. The general, credited in Washington with salvaging the US mission in Iraq, acknowledged that the Afghan governments police were often unpopular among the local population. There is truth, in fact, to the fact that the police in particular have image problems that are based on reality, he said.