NEW YORK - Following Secretary of State Hillary Clinton's tough warning against any future militants' attacks on the U.S. from the Pakistani soil, the American military commander in Afghanistan, Gen. Stanley McChrystal, stepped up pressure on Pakistan to move against The Taliban and al-Qaeda in tribal areas, The New York Times reported on its website Saturday afternoon. Gen. McChrystal, who met with the Pakistan Army chief, Gen. Ashfaq Parvez Kayani, at his headquarters on Friday, called for an early military offensive in North Waziristan, the newspaper said in a dispatch from Islamabad, citing officials who spoke on the condition of anonymity because of the delicacy of continuing diplomatic efforts here. Speaking to CBS' "60 Minutes) news programme, Mrs. Clinton said Pakistan Pakistan would face unspecified "severe consequences" if locally based militants succeeded in attacking the United States. Faisal Shahzad, 30, a U.S.citizen of Pakistani origin who is charged with attempting to detonate a bomb in New York's Times Square, has told American investigators that he had received training in North Waziristan, the main base for the Pakistani Taliban, Al Qaeda and other militant groups, according to American media reports. "The new pressure from Washington was characterized by both the Pakistani and American officials as a sharp turnaround from the relatively polite encouragement adopted by the Obama administration in recent months," The Times said. "And it comes amid increasing debate within the administration about how to expand the American militarys influence and even a boots-on-the-ground presence on Pakistani soil. "Though the bombing in Times Square failed, Mr. Shahzads ability to move back and forth between the United States and Pakistan has heightened fears in the Obama administration that another attempt at a terrorist attack could succeed," the dispatch added. We are saying, 'Sorry, if there is a successful attack, we will have to act within Pakistan, one of the American officials was quoted as saying. "That issue has been a source of growing tension between the countries. Pakistani officials, already alarmed by the increase in American drone aircraft attacks against militants in northwestern Pakistan, have been extremely sensitive about any hint that American ground troops could become involved in the fight. And attempts by the United States to increase the presence of Special Operations forces there even in an advisory or training role have been met with great resistance by the Pakistanis', The Times correspondent Jane Parlez wrote. The Pakistani military has stepped up its campaigns against militants in the past year, including an offensive in South Waziristan that has been praised by American officials. It has said that it is preparing to take up the fight against militants in North Waziristan. But Pakistani officials have insisted that the expanded campaign will happen completely on their own terms, and they have warned the Obama administration not to push so hard that it uses up the good will it has tried to foster here. "But the Americans urgency has been increasing on multiple fronts," the dispatch said. With an intensified American military campaign raging against the Taliban next door in Afghanistan, and now with the renewed evidence of Pakistani sources for plots to attack on American soil, it was clear the Pakistani government had to do more, and more urgently, a senior American official said Saturday. General Kayani, with whom General McChrystal has forged a positive relationship, was essentially told, 'You cant pretend any longer that this is not going on, another American official was quoted as saying. 'We are saying you have got to go into North Waziristan. The American ambassador to Pakistan, Anne Patterson, met Pakistans president, Asif Ali Zardari, after the failed bombing and used forceful language to convey the American point that the Pakistanis had to move more assertively against the militants threaded through the society, a Pakistani official was cited as saying. The element of threat is definitely different from the last few months, Tariq Fatemi, a former Pakistani ambassador who also served in the United States, was quoted as saying.