ISLAMABAD (Reuters) - Secretary of State Hillary Clinton said on Friday that Pakistan needed to take decisive steps against Islamist militancy and that relations between the two allies, tense since the killing of Osama bin Laden, had reached a turning point.
Clinton, the most senior U.S. official to visit Pakistan since U.S. Navy SEALS killed the al Qaeda leader in a compound outside Islamabad this month, appeared to be trying to smooth over strains, repeating that there was no evidence that any top Pakistani officials had known of bin Laden's whereabouts.
But she also said she had asked Pakistani President Asif Ali Zardari, Prime Minister Yusuf Raza Gilani as well as army chief General Ashfaq Kayani to do more to fight militants.
"This was an especially important visit because we have reached a turning point," a somber Clinton told reporters, after meeting the Pakistani officials with chairman of U.S. Joint Chiefs of Staff Admiral Mike Mullen.
"We look to Pakistan, to the government of Pakistan to take decisive steps in the days ahead."
Clinton declined to elaborate on those steps were but a U.S. official traveling with her suggested they may include special operations to attack militants.
"A lot of those things are quite sensitive. They are people who threaten Pakistan; they are people threaten Afghanistan; they are people who threaten the United States -- or activities that threaten Pakistan, Afghanistan, the United States," the official, who spoke on condition of anonymity, told reporters as Clinton flew back to the United States.
The discovery of bin Laden in a garrison town just 50 km (30 miles) from the capital on May 2 raised fresh doubts about Pakistan's reliability as a U.S. partner against militancy.
Clinton said Pakistani officials had told her "someone, somewhere" had been providing support for bin Laden in Pakistan, but reiterated there was no evidence of any sort of complicity by senior government officials.
"We are trying to untangle the puzzle of bin Laden's presence in Abbottabad," she said. "But I want to stress again, that we have absolutely no reason to believe that anyone in the highest level of the government knew that."
Clinton has emphasized the need to continue working closely with Pakistan, but her visit to Islamabad, came as U.S. lawmakers questioned whether Pakistan should be receiving billions of dollars in aid.
The Pakistan government welcomed the death of bin Laden but was outraged by the secret raid in Abbottabad, where bin Laden had lived for years, as a breach of its sovereignty.
Clinton was unapologetic over the raid, which was the latest in a series of incidents, from U.S. drone attacks inside Pakistan to the arrest of a CIA contractor for killing two Pakistanis, that have strained ties. Instead, she noted that Pakistan has a high concentration of militant leaders.
"For the past decade, many of the world's most vicious terrorists, including al Qaeda's most important leaders, have been living in Pakistan," she said.
She said the United States was attempting to split the Taliban in Afghanistan from al Qaeda, and encourage those militants to reconcile with the Afghan government. While acknowledging Pakistan's interests in a stable and secure Afghanistan, she noted that Pakistan needs to be more helpful.
"Many of the leaders of the Taliban continue to live in Pakistan," she said. "Pakistan has the responsibility to help us help Afghanistan by preventing insurgents from waging war from Pakistani territory."
There has been scant evidence of Islamist militancy abating despite billions of dollars in U.S. aid.
Friday, government jets attacked militants in the northwest, killing at least 16 of them, officials in the area said. There was no independent confirmation of the toll.
The attack came a day after a suicide car bomber killed 34 people outside a police station in the nearby town of Hangu.
Last weekend, militants stormed a heavily guarded naval base in the city of Karachi and fought a 16-hour battle with soldiers. Media said Friday a suspected militant had been detained in connection with that assault.
The militant attacks "have raised doubts about Pakistan's ability to quell militancy and protect its nuclear arsenal.
In the latest sign of deepening distrust between Washington and Islamabad, Pakistan has told the United States to halve the number of military trainers stationed in the country.
But a U.S. official said Washington had seen some signs of improved Pakistani cooperation, including the return of the tail section of a helicopter that crashed during the night-time raid in Abbottabad and access to bin Laden's wives.
In a further apparent move to reduce tension, Pakistani authorities agreed to allow the CIA to send a forensic team to scour bin Laden's compound for clues. A senior Pakistani military official said a CIA team had entered the compound, but said the team was not connected with Clinton's visit.
A U.S. official in Washington, who asked for anonymity while discussing sensitive information, said the forensic experts would look for evidence hidden in walls or buried under floors, but there was no guarantee they would find anything.
"I don't think she would have come if they hadn't already taken some of those initial steps," said a second U.S. official traveling with Clinton, saying ties were less frayed. "I think we have walked back from the brink from a week or two ago."
However, many U.S. lawmakers, skeptical that Pakistani officials did not know of bin Laden's presence, want to cut U.S. aid to Pakistan, which the White House views as vital to counter-terrorism and to hopes of stabilizing Afghanistan.
Ahead of her visit, Clinton said working with Pakistan was a strategic necessity for the United States, even as she pressed Islamabad to act more decisively against militants.
"The United States and Pakistan have worked together to kill or capture many ... terrorists here on Pakistani soil," she said. "This could not have been done without close cooperation between our governments, our military and our intelligence agencies. But we both recognize there is still much more work required, and it is urgent."
Writing by Zeeshan Haider: Editing by Alistair Scrutton and Maria Golovnina