WASHINGTON - With two missile strikes over the past week, the Obama administration has expanded the covert war run by the Central Intelligence Agency inside Pakistan, attacking a militant network seeking to topple the Pakistani government.
The missile strikes on training camps run by Baitullah Mehsud represent a broadening of the American campaign inside Pakistan, which has been largely carried out by drone aircraft. Under President Bush, the United States frequently attacked militants from Al Qaeda and the Taliban involved in cross-border attacks into Afghanistan, but had stopped short of raids aimed at Mr. Mehsud and his followers, who have played less of a direct role in attacks on American troops.
The strikes are another sign that President Obama is continuing, and in some cases extending, Bush administration policy in using American spy agencies against terrorism suspects in Pakistan, as he had promised to do during his presidential campaign. At the same time, Mr. Obama has begun to scale back some of the Bush policies on the detention and interrogation of terrorism suspects, which he has criticized as counterproductive.
Mr. Mehsud was identified early last year by both American and Pakistani officials as the man who had orchestrated the assassination of Benazir Bhutto, the former prime minister and the wife of Pakistan's current president, Asif Ali Zardari. Mr. Bush included Mr. Mehsud's name in a classified list of militant leaders whom the C.I.A. and American commandos were authorized to capture or kill.
It is unclear why the Obama administration decided to carry out the attacks, which American and Pakistani officials said occurred last Saturday and again on Monday, hitting camps run by Mr. Mehsud's network. The Saturday strike was aimed specifically at Mr. Mehsud, but he was not killed, according to Pakistani and American officials.
The Monday strike, officials say, was aimed at a camp run by Hakeem Ullah Mehsud, a top aide to the militant. By striking at the Mehsud network, the United States may be seeking to demonstrate to Mr. Zardari that the new administration is willing to go after the insurgents of greatest concern to the Pakistani leader.
But American officials may also be prompted by growing concern that the militant attacks are increasingly putting the civilian government of Pakistan, a nation with nuclear weapons, at risk.
For months, Pakistani military and intelligence officials have complained about Washington's refusal to strike at Baitullah Mehsud, even while C.I.A. drones struck at Qaeda figures and leaders of the network run by Jalaluddin Haqqani, a militant leader believed responsible for a campaign of violence against American troops in Afghanistan.
According to one senior Pakistani official, Pakistan's intelligence service on two occasions in recent months gave the United States detailed intelligence about Mr. Mehsud's whereabouts, but said the United States had not acted on the information. Bush administration officials had charged that it was the Pakistanis who were reluctant to take on Mr. Mehsud and his network.
The strikes came after a visit to Islamabad last week by Richard C. Holbrooke, the American envoy to Pakistan and Afghanistan.
In a telephone interview on Friday, Mr. Holbrooke declined to talk about the attacks on Mr. Mehsud. The White House also declined to speak about Mr. Mehsud or the decisions that led up to the new strikes. A C.I.A. spokesman also declined to comment.
Senior Pakistani officials are scheduled to arrive in Washington next week at a time of rising tension over a declared truce between the Pakistani government and militants in the Swat region.
While the administration has not publicly criticized the Pakistanis, several American officials said in interviews in recent days that they believe appeasing the militants would only weaken Pakistan's civilian government. Mr. Holbrooke said in the interview that Secretary of State Hillary Rodham Clinton and others would make clear in private, and in detail, why they were so concerned about what was happening in Swat, the need to send more Pakistani forces to the west, and why the deteriorating situation in the tribal areas added to instability in Afghanistan and threats to American forces.
Past efforts to cut deals with the insurgents failed, and many administration officials believe that they ultimately weakened the Pakistani government.
But Obama administration officials face the same intractable problems that the Bush administration did in trying to prod Pakistan toward a different course. Pakistan still deploys the overwhelming majority of its troops along the Indian border, not the border with Afghanistan, and its intelligence agencies maintain shadowy links to the Taliban even as they take American funds to fight them.
Under standard policy for covert operations, the C.I.A. strikes inside Pakistan have not been publicly acknowledged either by the Obama administration or the Bush administration. Using Predators and the more heavily armed Reaper drones, the C.I.A. has carried out more than 30 strikes since last September, according to American and Pakistani officials.
The attacks have killed a number of senior Qaeda figures, including Abu Jihad al-Masri and Usama al-Kini, who is believed to have helped plan the 1998 American Embassy bombings in East Africa and last year's bombing of the Marriott Hotel in Islamabad.
American Special Operations troops based in Afghanistan have also carried out a number of operations into Pakistan's tribal areas since early September, when a commando raid that killed a number of militants was publicly condemned by Pakistani officials. According to a senior American military official, the commando missions since September have been primarily to gather intelligence.
The meetings hosted by the Obama administration next week will include senior officials from both Pakistan and Afghanistan; Mrs. Clinton is to hold a rare joint meeting on Thursday with foreign ministers from the two countries. Also, Gen. Ashfaq Parvez Kayani, the Pakistani Army chief, will meet with Defense Secretary Robert M. Gates and Adm. Mike Mullen, the chairman of the Joint Chiefs of Staff. Lt. Gen Ahmed Shuja Pasha, the head of Pakistan's military spy service, will accompany General Kayani.
Eric Schmitt contributed reporting from Islamabad, Pakistan.