In a blunt warning, US has threatened to take "unilateral action" by sending its troops to Pakistan to shut down Taliban and other terrorist camps there, if Islamabad does not take decisive action against them.
The Americans want the Pakistanis to target Haqqani network based in north Waziristan and Taliban supremo Mullah Omar and the members of the groups top Shura, believed to be hiding in Baluchistan.
Washington feels that Pakistani forces have so far refused to attack against these two Taliban groups, The New York Times reported quoting American and Pakistani officials.
The Times said, "The US 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 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, Obama's national security adviser, and John O Brennan, the White House counter terrorism chief, met with the heads of Pakistan's military and its intelligence service," The paper said.
US officials said the message 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.
A senior administration official, asked about the encounter, declined to go into details but added quickly, "I think they read our intentions accurately."
A Pakistani official who has been briefed on the meetings said, "Jones's message was if Pakistani help wasn't forthcoming, the United States would have to do it themselves."
American commanders said earlier this year that they were considering expanding drone strikes in Pakistan's lawless tribal areas, but General Jones's comments marked the first time that the US bluntly told Pakistan it would have to choose between leading attacks against the insurgents inside the country's borders or stepping aside to let the Americans do it.
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 administration's counterterrorism campaign, New York 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 US forces conducting a ground raid on Pakistani soil.
But the raid caused a political furor in Pakistan, with the country's top generals condemning the attack, and the US backed off what had been a planned series of such strikes.
"We've offered them a strategic choice," one administration official was quoted as saying by the daily.
"And we've heard back almost nothing." Another administration official said, "Our patience is wearing thin." At the same time, the White House officially refused to make any comment on the harsh message delivered to Pakistan.
"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," Tommy Vietor, a White House spokesman was quoted as saying by The New York Times.
The daily said during his intensive review of Pakistan and Afghanistan strategy, 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 resupply. But the administration has said little about the Pakistani part of the strategy, it noted.
"We concluded early on that whatever you do with Pakistan, you don't want to talk about it much," a senior presidential aide said last week. "All it does is get backs up in Islamabad," the presidential aide was quoted as saying.
Even before Obama announced his decision last week, the White House had approved an expansion of the CIA's drone programme in Pakistan's lawless tribal areas.
Pakistani officials, wary of civilian casualties and the appearance of further infringement of national sovereignty, are still in discussions with American officials over whether to allow the CIA to expand its missile strikes into Baluchistan for the first time, a politically delicate move because it is outside the tribal areas.
American commanders say this is necessary because Mullah Omar, the Taliban leader who ran Afghanistan before the 2001 invasion, and other Taliban leaders are hiding in Quetta, the capital of Baluchistan Province.
Pakistani officials also voice concern that if the Pakistani Army were to aggressively attack the two groups that most concern the US, the militants would respond with waves of retaliatory bombings, further undermining the weak civilian government.