NEW YORK In what appears to taken the shape of campaign, the Obama administration has again asked Pakistan to do more in fighting the Taliban inside its borders, with the warning that the U.S. will use considerably more force on the Pakistani side of the border to shut down Taliban attacks on American forces in Afghanistan. The blunt message was delivered in a tense encounter in Pakistan last month, before President Barack Obama announced his new war strategy, when Gen. James Jones, the national security adviser, and John Brennan, the White House counterterrorism chief, met with the heads of Pakistans military and its intelligence service, according to a report in The New York Times on Tuesday. Of late senior administration officials have turned the focus on Pakistan after piling pressure on Afghanistans President Hamid Karzai to clean up corruption in his country as part of a US strategy shift. SIGNIFICANT COMMENT I have to say that corruption is critical to our success, but its not the governing issue in this war, Special US Envoy Richard Holbrooke said in a significant comment during a CNN interview. To me the most important issue for our success is dealing with the sanctuary in Pakistan. Holbrooke appears to be saying that corruption is no longer a problem with the Obama administration, a move that should please some actors in the region. About US message to Pakistan, united States officials said it did not amount to an ultimatum, but rather it was intended to prod a reluctant Pakistani military to go after Taliban insurgents in Pakistan who are directing attacks in Afghanistan. 'BALD WARNING For their part the Pakistanis interpreted the message as a fairly bald warning that unless Pakistan moved quickly to act against two Taliban groups they have so far refused to attack, the United States was prepared to take unilateral action to expand predator drone attacks beyond the tribal areas and, if needed, to resume raids by Special Operations forces into the country against Al Qaeda and Taliban leaders, the Times said. A senior administration official, asked by the Times about the encounter, declined to go into details but added quickly, I think they read our intentions accurately. An unnamed Pakistani official who has been briefed on the meetings said, Joness message was if that Pakistani help wasnt forthcoming, the United States would have to do it themselves. American commanders said earlier this year that they were considering expanding drone strikes in Pakistans lawless tribal areas, but General Joness comments marked the first time that the United States bluntly told Pakistan it would have to choose between leading attacks against the insurgents inside the countrys borders or stepping aside to let the Americans do it. The recent security demands followed an offer of a broader strategic relationship and expanded intelligence sharing and non-military economic aid from the United States, the dispatch said. Pakistans politically weakened president, Asif Ali Zardari, replied in writing to a two-page letter that General Jones delivered from Mr. Obama. But Mr. Zardari gave no indication of how Pakistan would respond to the incentives, which were linked to the demands for greatly stepped-up counterterrorism actions. Weve offered them a strategic choice, one administration official was quoted as saying, describing the private communications. And weve heard back almost nothing. Another administration official said, Our patience is wearing thin. Asked Monday about the exchange, Tommy Vietor, a White House spokesman, said, We have no comment on private diplomatic correspondence. As the president has said repeatedly, we will continue to partner with Pakistan and the international community to enhance the military, governance and economic capacity of Afghanistan and Pakistan. The implicit threat of not only ratcheting up the drone strikes but also launching more covert American ground raids would mark a substantial escalation of the administrations counterterrorism campaign, the Times said. American Special Operations forces attacked Qaeda militants in a Pakistani village near the border with Afghanistan in early September 2008, in the first publicly acknowledged case of United States forces conducting a ground raid on Pakistani soil. But the raid caused a political furore in Pakistan, with the countrys top generals condemning the attack, and the United States backed off what had been a planned series of such strikes. During his intensive review of Pakistan and Afghanistan strategy, officials say, Obama concluded that no amount of additional troops in Afghanistan would succeed in their new mission if the Taliban could retreat over the Pakistani border to regroup and re-supply. But the administration has said little about the Pakistani part of the strategy. During his speech at West Point last week, Obama said, Our success in Afghanistan is inextricably linked to our partnership with Pakistan. But for the rest of the speech he referred to the country in the past tense, talking about how there have been those in Pakistan whove argued that the struggle against extremism is not their fight, and that Pakistan is better off doing little or seeking accommodation with those who use violence. He never quite said how his administration views the Pakistanis today, and two officials said that Obama used that construction in an effort not to alienate the current government or the army, led by Gen. Ashfaq Parvez Kayani, the Times said.