WASHINGTON (AFP) - For the United States, much may be riding on an unlikely relationship between Americas highest ranking military officer and Pakistans powerful army chief. Over cups of tea and the occasional cigar, the avuncular American admiral and the reserved general talk about terrorist threats and sensitive military operations in a region President Barack Obama deems the 'central front in the fight against Al-Qaeda. Admiral Mike Mullen, Chairman of the Joint Chiefs of Staff, said he has gone out of his way to build a rapport with his Pakistani counterpart, General Ashfaq Parvez Kayani, speaking to him regularly and holding 10 face-to-face meetings since November 2007. Im a big believer that the worst time to try to get to know someone is during a crisis, so this constant dialogue I have with General Kayani is vital, said Mullen, responding to questions from AFP by email. Although the two come from different worlds - the US admiral is the son of a successful Hollywood publicist and Kayani comes from a working-class family headed by a father who was a non-commissioned officer - a bond of trust has begun to form, Mullens spokesman Captain John Kirby said. The meetings are conducted with few aides and far from public view. Typically we meet alone with no note takers, Mullen said. As arguably the most powerful man in nuclear-armed Pakistan, Kayani is a pivotal figure for the Obama administration as it seeks to contain insurgents linked to Al-Qaeda who are challenging the Kabul government and Islamabads authority. Kayani and the countrys political leadership face growing demands from Washington to take decisive action against the militants who are alleged to enjoy support from the countrys intelligence service. Mullen praised Kayani for taking 'bold steps against the insurgents, saying he has moved troops to the Afghan border, cracked down against militants in Bajaur and equipped the paramilitary Frontier Corps in the northwest. I believe the relationship I have with General Kayani has been very productive, he said. Ive been encouraged by what he has done and, quite frankly, by what he has not done. The admiral said Kayani and the Pakistani government did not allow recent tensions with India over attacks in Mumbai to distract them from 'the real struggle they face right now deep inside their borders. Kayani is not the first military chief in Pakistan with a reputation for competence to raise hopes in Washington. He was named to his post in 2007 by General Pervez Musharraf, the former military chief and president who initially won praise in the aftermath of the September 11 attacks. But in the end, Musharrafs promised crackdown against extremists failed to materialise. Musharraf 'is a deceitful man who led us up the garden path, said Simon Henderson, a senior fellow at the Washington Institute for Near East Policy. The American experience with Musharraf serves as a cautionary tale as US officials try to court Kayani. Once a military assistant to the late prime minister Benazir Bhutto as well as a trusted protege of her rival Musharraf, Kayani has proven himself a 'chameleon in surviving Pakistans treacherous political waters, Henderson said. Although Mullen credits him for his role in defusing last months political crisis between President Asif Zardari and his rival Nawaz Sharif, it remains to be seen if Kayani is able or willing to carry out the kind of crackdown on militants that Washington wants. As recently as 2007, Kayani served as director of the Inter-Services Intelligence (ISI) agency, the spy service at the heart of Western anxiety over Pakistan. Mullen said he was realistic about his talks with Kayani. Im not saying we take everything at face value - we remain concerned over the degree to which there are still linkages between ISI and the Taliban, for instance - but we have to better appreciate what they are up against in terms of their own troubled past, he said. Kayani insists the ISI has washed its hands of the militants and that its influence has been wildly overstated. He claims the ISI has been purged of extremists and the leadership is consciously looking out for people within the organisation who might be undermining the entire anti-terror effort, said Imtiaz Gul, chair of the Centre for Research and Security Studies (CRSS) in Islamabad. When talking about Kayani, Mullen refers to the best-selling book 'Three Cups of Tea, by Greg Mortenson, the American rock climber who has dedicated his life to building schools in remote villages along Pakistans border. It is said in that part of the world, after one cup of tea, you are strangers. After two cups you are friends. And after three cups of tea, you become family, Mullen said. Id like to believe I am working on at least my second cup of tea with him.