Hillary Clinton is due to meet Pakistani leadership during her visit
The US Secretary of State Hillary Clinton has arrived in Pakistan on a surprise visit aimed at soothing tensions between the two countries.
It's the first such high-level visit to Pakistan since the killing of al-Qaeda leader Osama Bin Laden on 2 May.
Islamabad is unhappy that it had no prior knowledge of the raid on Bin Laden's compound in Abbottabad.
It comes a day after the US announced it was withdrawing some of its troops from Pakistan, at Islamabad's request.
The Pentagon said it had received a request from the Pakistani government to reduce its presence in the country.
ANALYSIS
Kim Ghattas Travelling with Hillary Clinton
We landed amidst very tight security, with choppers flying overhead. The roads were cleared of all traffic and Pakistani paramilitary officers lined the streets. The convoy of armoured cars drove at breakneck speed.
This is Mrs Clinton's third visit to Pakistan and seems the most tense of all on a security level. But the meetings will also be tense. She'll be asking the Pakistanis for the same things she did the first two times, but with more urgency.
The US wants further co-operation on counter-terrorism and on reconciliation in Afghanistan. But Mrs Clinton has also been pressing the Pakistanis to do more and better on tax collection from Pakistan's elite to fill the coffers of the state.
The US currently gives Pakistan $3bn in aid every year.
Relations between US and Pakistan are always complex and fragile but they are particularly volatile at the moment.
In Washington, suspicion is rife that some in Pakistan knew of Osama Bin Laden's hiding place.
During her visit, Mrs Clinton is to meet Pakistani President Asif Ali Zardari, army chief General Ashfaq Kayani and Ahmad Shuja Pasha, chief of Pakistan's powerful intelligence agency ISI.
The secretary of state is accompanied by chairman of the US Joint Chiefs of Staff Admiral Mike Mullen.
They are expected to demand more cooperation from Pakistan in the fight against al-Qaeda and Taliban militants.
Some in Washington believe that Pakistani intelligence works closely with violent extremist groups.
Meanwhile, US media reports say that Pakistan will allow the CIA to examine Bin Laden's compound in Abbottabad.
A forensics team is expected to arrive within days along with sophisticated equipment to find material that may be embedded behind walls, inside safes or buried underground.
An incredible amount of intelligence was recovered during the raid, but officials said this could be an opportunity to find out more about al-Qaeda.
It could also help improve ties with Pakistan, they said.
http://www.bbc.co.uk/news/world-south-asia-13570803
