WASHINGTON  - Defense Secretary Leon Panetta all but ruled out an apology over an airstrike last year that killed 24 Pakistani soldiers and badly set back efforts to improve US-Pakistani ties, saying it was ‘time to move on.’Panetta, in an interview with Reuters on Thursday, suggested that past expressions of regret and condolences were enough and held out hope that troubled talks on re-opening Pakistani supply routes for the Nato war effort could succeed anyway.Asked whether he would oppose any further apology, Panetta said: “We’ve made clear what our position is, and I think it’s time to move on.” “If we keep going back to the past, if we keep beating up each other based on past differences, we’ll never get anywhere,” he said.“The time now is to move forward with this relationship, on the (supply routes), on the safe havens, on dealing with terrorism - on dealing with the issues that frankly both of us are concerned about,” Panetta said.But in his interview with Reuters, he appeared to temper those remarks, saying: “It’s a complicated and frustrating relationship. But it’s a necessary relationship and one that we’ve got to continue to work at on both sides.” At the same time, Panetta acknowledged pressures building in Congress to put conditions on aid to Pakistan.“It’s not something that we’re pushing in the Congress. But the reality is that the more problems we have, the more difficult it’s going to be in the Congress to continue to provide assistance without conditions,” Panetta said.He also acknowledged the likelihood that a protracted cut-off of the supply routes, costing Americans millions of dollars a day, would ultimately impact aid to Pakistan as well.Nearly one year ago, US Defense Secretary Leon Panetta predicted the strategic defeat of al Qaeda was within reach if the United States could kill or capture up to 20 leaders of the core group and its affiliates.Panetta disclosed that only a “small handful” of the individuals on that original list remained on the battlefield and that Saudi Arabia - the birthplace of late Qaeda leader bin Laden - was reporting a drop-off in recruitment.“We’ve not only impacted on their leadership, we’ve impacted on their capability to provide any kind of command and control in terms of operations,” Panetta said. The US defense chief visited Saudi Arabia on Wednesday and after paying US condolences over the death of the late crown prince, spoke about al Qaeda with one of his sons, Saudi Prince Mohammed bin Nayef, who has run the kingdom’s operations against Qaeda as a deputy interior minister.“I asked him the question - as a result of the bin Laden raid, as a result of what we’ve done to their leadership, where are we with Qaeda,” Panetta recounted, adding that Qaeda and bin Laden “came out of Saudi Arabia.”“Bin Nayef said, ‘For the first time, what I’m seeing is that young people are no longer attracted to Qaeda in Saudi Arabia.’” Panetta did not single out which leaders from his target list last year remained, but current Qaeda chief Ayman al-Zawahiri is one he named last year and who is still believed to be living in the border region of Afghanistan and Pakistan. Asked how many targets remained, Panetta said, “It’s a small handful and it’s growing smaller all the time.”After addressing questions about the future of al Qaeda’s top leadership, Panetta shifted his focus to the group’s ability to survive as a movement at all.“We’ll keep the pressure on at the top and we’ll keep going after their leadership,” Panetta said.“But the real issue that will determine the end of Qaeda is when they find it difficult to recruit any new people.”Panetta also defended the Obama administration’s decision not to arm the Syrian rebels.