ISLAMABAD (Online) - While expressing concern over the dismissal of Prime Minister's Advisor on National Security Mehmud Ali Durrani, US has insisted on Pakistan to reinstate him by withdrawing the sacking orders. The demand was made by US Ambassador to Pakistan Ann W Patterson while talking to President Asif Ali Zardari and Prime Minister Yousuf Raza Gilani at Aiwan-e-Sadr on Thursday, sources informed Online. It merits mentioning here that PM Gilani sacked Mahmood Durrani for not consulting him before announcing that the sole Mumbai attacker Ajmal Kasab was a Pakistani citizen. During the meeting, issues related to dismissal of Mr Durrani, tension between Pakistan and India, nationality of Ajmal Kasab and current regional security situation were discussed in length, sources said. Ms Peterson insisted the President and Prime Minister to withdraw dismissal orders of Durrani as NSA and reinstate him. She also urged Pakistan to take special measures to break up the network of banned outfits involved in Mumbai incident after the conformation of Ajmal Kasab's nationality. Later, the President and Prime Minister held one-to-one meeting that lasted more than one hour in which they discussed situation following the dismissal Mr Durrani and nationality of Ajmal Kasab. Different names including Tariq Aziz, top aide of former President Pervez Musharraf, as new national security advisor were mulled, sources said. The sources said the Prime Minister took the President into confidence over sacking of Mehmud Durrani after his irresponsible behaviour for not taking the Premier and other stakeholders into confidence and creating lack of coordination on matters of national security. Speaking on the occasion, President asked Indian leadership to reciprocate Pakistan's proposal constructively instead of leveling allegations with regard to Mumbai attack. The President added Pakistan have no aggressive design against any country while perpetrators of Mumbai attack whosoever they are brought to justice in accordance with country's law if they are in Pakistan. President Zardari went on to say that Pakistan doest want tension in the region and demonstrated responsible behaviour after Mumbai attacks but it was waiting for India's constructive response.