U.S. accusations of links between Pakistan?s spy agency and one of the deadliest terrorist networks operating in Afghanistan have severely strained an already tense relationship. As the dispute continues, both Washington and Islamabad have turned to China for assistance. China has so far been unwilling to play a more prominent role in Pakistan.
Pakistan - China relations
This week, U.S. Secretary of State Hillary Clinton called for Chinese and U.S. officials to begin a dialogue over Pakistan.
In recent months, Chinese and Pakistani officials have praised the close ties between their two countries. Trade last year totaled nearly $9 billion. Beijing sells many arms to Pakistan, including fighter jets and frigates, and is behind much of Pakistan's infrastructure projects. These include ports on the Arabian Sea, planned oil and gas pipelines and a railway network.
But that has not meant China is ready to take a higher profile role with Pakistan. Chinese Foreign Ministry spokesman Hong Lei this week brushed aside questions about the strengthening bonds between Beijing and Islamabad.
He also refused to comment on Hillary Clinton's calls for talks on Pakistan or whether China is planning to increase its ties or investments to the country.
However, Hong says China hopes the international community respects Pakistan's integrity and international sovereignty. He said Beijing hopes Pakistan and the United States will improve their relationship, which will improve the region?s peace, stability and development.
Economy vs security
For all of China?s economic investments in Pakistan, Beijing remains concerned about the security situation in the country. This week, a Chinese mining company pulled out of a $19 billion mining and industrial development project over security concerns.
China has also sought Pakistan?s help in fighting what it says is a terrorist threat from Uighur separatists training in remote areas of Pakistan, who then launch attacks on Chinese interests in the restive far western Chinese province of Xinjiang.
China views Pakistan as its closest ally in South Asia and, as importantly, among Islamic countries. Pakistan increasingly sees China as a possible counterbalance to the rising might of its arch rival India, and as a possible alternative to its increasingly strained relationship with Washington.
However analyst James Brazier of international risk assessment consultants, IHS, says that for both countries, their interests in Afghanistan remain the key part of their relationship.
"This is a huge, slightly brittle politically, energy-rich region in China's back yard and it really can't afford for this sort of Taliban-style insurgency to flow from Afghanistan and up into Tajikistan and Kyrgyzstan and beyond - and possibly also into Xinjiang," said Brazier. "So Pakistan could be quite crucial as to how China manages the risks in what is still a very uncertain and worrying picture in Afghanistan."
Since the U.S. raid that killed Osama bin Laden, Pakistan has played up its ties to China and officials have shuttled back and forth between the two countries offering words of support and encouragement.
U.S. officials have publicly embraced these increased ties. This week, Admiral Robert Willard, the commander of the U.S. Pacific Command, told reporters that Washington and Beijing have a mutual desire for peace and stability in Pakistan and in all countries in one of the most unstable parts of the world.
"I think China recognizes, just as the U.S. does, the importance of an outcome in all of this where Pakistan is - winds up a very stable and peaceful state, and Afghanistan, Pakistan, India relations continue to be stable and managed," said Willard. "So I think China?s interests and U.S. interests in the region, while we don?t spend a lot of time dwelling on this, are inherently convergent and desire a stable South Asia."
For now, Pakistan continues to reject U.S. accusations that its spy agency supports the al-Qaida linked Haqqani terrorist network. Pakistani officials say their country cannot be forced to do more in the fight against militants. Amid the public disagreement, China continues to stay largely quiet, leaving both Washington and Islamabad to guess its ultimate intentions.