WASHINGTON - Admiral Mike Mullen, the Chairman of the US Joint Chiefs of Staff, said Monday he was comfortable that Pakistans nuclear weapons were secure, but he was gravely concerned about the progress the Taliban had made inside both Pakistan and Afghanistan. Mullen, who visited Pakistan and Afghanistan last week, added that while fighting continues in Iraq, and the US remains committed to the mission, the main effort in our strategic focus from a military perspective must now shift to Afghanistan. In a news briefing at Pentagon, he offered a mixed assessment about security in the region in advance of tripartite summit meetings this week between President Barack Obama and President Asif Ali Zardari and his Afghan counterpart Hamid Karzai. Admiral Mullen said he did not think for now that the US had to worry that militants would get hold of Pakistans nuclear arsenal. We all recognise, obviously, the worst downside with respect to Pakistan is that those nuclear weapons come under the control of terrorists, he said. I dont think thats going to happen. I dont see that in any way imminent whatsoever at this particular point in time. Underscoring the need to shifting from Iraq to Afghanistan, Mullen said, I say that with the full knowledge that we still have about 136,000 American troops in Iraq, and that the fighting there isnt over. We remain committed to the mission weve been given in Iraq, make no mistake, and we will stay there long enough, in keeping with their agreement, to ensure the Iraqis can provide for their own security. Nonetheless, he said, Afghanistan has been an economy-of-force operation for far too long. Admiral Mullen said it was no longer about can-do anymore, this is about must-do, and we must do more over at least the next two years, starting now. Admiral Mullen declined to offer a public assessment of the leadership of Zardari, who Pentagon officials consider increasingly weak, but he did say that the Pakistani leader needed to face a number of economic and political challenges at home. Mullen said he is pleased with progress made by the Pakistan Army in controlling the Buner region, but he has a limit to what he knows. He said that during his trip last week he saw that the Pakistan Army is undergoing intensive training under Pakistan Army Chief Gen Ashfaq Parvez Kayani. He said the Taliban are pretty consistent with their fighting, but lately have been more coordinated and operating at a higher level. He said he is as concerned as he was a couple weeks ago that Pakistani security is at a tipping point, but has seen several significant movements in operations on the part of the Pakistan Army. Theyve had some positive impact. Too soon to tell how long its going to be sustained and where it goes, he said. AFP adds: Mullen, who has just returned from a trip to the Middle East and Asia, added that he remained concerned about the situation in Pakistan. The Taliban, aided by Al-Qaeda and other extremists in safe havens across the border, are recruiting through intimidation, controlling through fear, and advancing an unwelcome ideology through thuggery, he said. Im gravely concerned about the progress they have made in the south and inside Pakistan, he said. The consequences of their success directly threaten our national interests in the region and our safety here at home. Im encouraged by recent military operations in Buner, but it is too soon to tell whether those operations will have a decided impact over the long term, Mullen added. Americans would like to see this move much more quickly, Mullen said, acknowledging though that this is their country, sovereign country, and the Pakistani people and the Pakistani leadership are going to move at their pace. Meanwhile, US Defense Secretary Robert Gates said Monday part of his focus in Saudi Arabia will be on its potential influence in Pakistan. I think that the Saudis in particular have considerable influence in Pakistan, and so I think whatever they can do to help bring the Pakistanis together in a broader sense to deal with the challenge to the government in Islamabad would be welcome, he said. Gates also welcomed any help Saudi officials could give to Pakistans fragile government. Gates is on a delicate mission to soothe concerns from Mideast allies about American efforts to open diplomatic relations with Iran. Gates is coming to the Middle East as 21,000 more American troops prepare to head to Afghanistan. On that front, the defense secretary reiterated that the United States is open to some form of reconciliation with certain elements of the Taliban. But he said that as long as the Taliban perceives momentum on its side, the prospects for political reconciliation are pretty limited. And when it comes, political reconciliation has to be on the terms of the Afghan government, which must have a monopoly on the armed force in that country.