WASHINGTON - The US military will reserve the 'right of last resort to deal with threats inside Pakistan , but it would prefer to enable the Pakistani military to do the job itself, a top US commander said on Monday. General David Petraeus , the head of US Central Command, was speaking in an interview with FOX news as the Obama administration prepares to step up the fight against al Qaeda and the Taliban along the Pak-Afghan border. Asked about reports that Pakistan is not fully on board, Petraeus said that the US military is putting 'additional focus on rooting out ties between Pakistans intelligence service and the Taliban. One incident of obvious cooperation between the Pak intelligence community and extremists has already been uncovered, he added. 'There is a case in the past year or so that we think was unambiguous. There appears to have been a warning prior to a Pakistani operation, Petraeus said. But he said trust between the two countries will be key as President Obama seeks more Pak cooperation and calls for billions in aid to the country. 'I think we are building that kind of trust. And thats the way I think is the best description for that. And its hugely important that trust be built, Petraeus said, pointing to 'gradually increasing intelligence sharing among Afghan, Pakistani and US forces along the border. Obama, in unveiling his regional plan for Afghanistan and Pakistan on Friday and said the US will 'insist that action be taken, one way or another, when we have intelligence about high-level terrorist targets. He said on Sunday that 'were going after such targets, though the US will need to work with Pak govt to do so. He did not specifically say US troops could be sent into the country. Asked about the Presidents comments, Petraeus signaled that all options would be on the table. 'I think we would never give up, if you will, the right of last resort if we assess something as a threat to us, noting that what we want to do is enable the Pakistanis, help them, assist them to deal with the problem that we now think, and their leaders certainly now think, represents the most important threat to their country, not just to the rest of the world, he said. Pakistan resents the unmanned US drone strikes to take out terrorist targets inside their border. But Petraeus said the US is mindful of perceptions in the region. 'It is hugely important that we be seen as good neighbours, as friends, certainly fierce warriors who will go after the enemy and stay after them but also as individuals who try to avoid civilian casualties whenever possible and are seen again as supporting the people and trying to help them achieve a better life, Petraeus said, specifically referring to the fight on the Afghan side of the border. On the Pakistani side, Petraeus acknowledged an effort to put a halt to any collaboration between Taliban members and individuals in Pakistani intelligence. 'There are some relationships that continue. It is not as clear as one would like. Theres certainly additional focus on that, Petraeus added. 'Obviously, weve had these conversations with our counterparts (in Pakistan). Obama has announced that hes sending 21,000 more troops to Afghanistan and is requesting $1.5 billion a year for the next five years in aid for Pakistan He is also planning to call for $2.8 billion just for Pakistans military. As to threats elsewhere in the region, Petraeus said Iran is still 'some years away from a nuclear weapon. 'They have low-enriched uranium that is about the amount that would be required perhaps to make a weapon, but there are many, many more steps that are required. 'You have to highly enrich it, he added. 'But are they a threat? Certainly.