NEW YORK - Admiral Michael Mullen late Wednesday afternoon confirmed the existence of a secret memo alleged to have been sent by President Asif Ali Zardari that the top US military officer had earlier not recollected receiving, a dispatch posted on Foreign Policy magazine said. The confirmation led Pakistans Ambassador to the United States Husain Haqqani, who became embroiled in the raging controversy over the memo, to offer his resignation to President Zardari. The FP dispatch said, Haqqani, who has long been a key link between the civilian government in Pakistan and the Obama administration, has also been battling for years with the Pakistani military and the Inter-Services Intelligence (ISI) - two organisations whose influence in Washington he has fought to weaken. That battle came to the fore of Pakistani politics this month due to the growing scandal known in Pakistan as 'memo-gate, which relates to a secret backchannel memo that was allegedly conveyed from Zardari to Mullen, through Pakistani-American businessman Mansoor Ijaz. Ijaz alleged in an Oct 10 op-ed in the Financial Times that on May 10, in the wake of Osama bin Ladens killing in Abbottabad, Zardari had offered to replace powerful military and intelligence leadership and cut ties with militant groups. Ijaz said he was directed to craft the memo by a senior Pakistani official close to Zardari. Ijaz has implied - and the Pakistani press has speculated - that this official was Haqqani. Last week, The Cable published a report on Mullens comments about the memo. Adm Mullen does not know Mr Ijaz and has no recollection of receiving any correspondence from him, Mullens spokesman Captain John Kirby said Nov 8. I cannot say definitively that correspondence did not come from him - the admiral received many missives as chairman from many people every day, some official, some not. But he does not recall one from this individual. Ijaz responded in an article in a Pakistani newspaper, in which he published extensive Blackberry Messenger conversations with the Zardari-linked Pakistani official, allegedly Haqqani. He insisted that the memo did, in fact, exist, and that it was delivered from Ijaz to Mullen through another secret go-between, this one a senior US government official. There can be no doubt a memorandum was drafted and transmitted to Admiral Mullen with the approval of the highest political level in Pakistan, and that the admiral received it with certainty from a source whom he trusted and who also trusted me, Ijaz wrote. Kirby told The Cable Wednesday that Mullen now acknowledges that the Ijaz memo does exist, that he did receive it but that he never paid any attention to it and took no follow up action. Adm. Mullen had no recollection of the memo and no relationship with Mr Ijaz. After the original article appeared on Foreign Policys website, he felt it incumbent upon himself to check his memory. He reached out to others who he believed might have had knowledge of such a memo, and one of them was able to produce a copy of it, Kirby said. That said, neither the contents of the memo nor the proof of its existence altered or affected in any way the manner in which Adm. Mullen conducted himself in his relationship with Gen Kayani and the Pakistani government. He did not find it at all credible and took no note of it then or later. Therefore, he addressed it with no one. Pakistani opposition leaders have seized upon the controversy. Meanwhile, the military has been pressuring Zardari to start an inquiry into the memo. In an interview with The Cable late on Wednesday afternoon, Haqqani confirmed that he will travel to Islamabad and has sent a letter to Zardari offering his resignation. At no point was I asked by you or anyone in the Pakistani government to draft a memo and at no point did I draft or deliver such a memo, Haqqani said that he had written in his letter to Zardari. Ive been consistently vilified as being against the Pakistani military even though I have only opposed military intervention in political affairs, Haqqani said that he wrote. Its not easy to operate under the shadow of innuendo and I have not been named by anyone so far, but I am offering to resign in the national interest and leave that to the will of the president. Haqqani declined to comment whether or not he played any role in the controversy surrounding the memo - for example, discussing it with Ijaz before or after the fact, as the scandal deepened. Its widely rumoured that Haqqani and Ijaz have known each other for many years. The dispatch said, It remains unclear whether Zardari had any knowledge of the memo at the time. In Islamabad, some speculate that Zardari may be trying to put an end to the memo-gate controversy by sacrificing Haqqani, but no decision has yet been made on whether or not Haqqani will step down. If he leaves, he will return to private life having played a key role in the US-Pakistan relationship during its most tumultuous period - a role that is mired in the secrecy and intrigue of Pakistani politics and diplomacy. According to Haqqani, he is the target of a media campaign backed by the supporters of the militarys role in politics because he has focused on building ties between the US and Pakistani civilian governments, rather than with the Pakistani military. Eighty per cent of Pakistanis dont want a good relationship with the US, and anyone who stands up for the United States can expect to be vilified, he said. Agencies add: I serve at the pleasure of the president of Pakistan and the prime minster of Pakistan. And I have communicated my willingness to resign or participate in any inquiry that brings to an end the vilification against the democratic government of Pakistan currently being undertaken by some elements in the country, said Husain Haqqani, a former journalist who has been Pakistans ambassador to Washington since 2008. Officials in the government were not immediately available to say whether Haqqanis offer had been accepted. While the identity of the Pakistani diplomat cited by Ijaz has never been confirmed, Haqqani is suspected by many politicians in his native country as the diplomat who approached Ijaz. In a conversation to Atlantic, Haqqani seemed simultaneously bemused and defiant said: I am a Pakistani, I will die a Pakistani, he said, when I asked him if he was going to seek asylum in the U.S. Ive lived in the United States so many years without seeking citizenship, and this is because I have a love for Pakistan. He went on to say that he will continue to serve as ambassador at the pleasure of his president. I have sought a role to play in the history of my country. I have not sought this as a job. I will continue to play this role, but I have offered my resignation as a way to defuse the current situation, in which a handful of journalists have blown out of all proportion an op-ed by a businessman. A growing concern in Washington is that Haqqanis life would be in danger should he return to Islamabad Ive heard people mention the chance of an Aquino-style airport assassination, but what would be more likely is that the military would place Haqqani under arrest and interrogate him about what the ISI sees as his attempts to subvert military authority. Many people in Washington assume or hope, more to the point that the Obama Administration is communicating to the Pakistani authorities its worry about Haqqanis safety. More to come, undoubtedly. The issue has snowballed in Pakistan - a key US ally in efforts to stabilize Afghanistan - into a bigger controversy. Analysts have warned that Haqqanis departure will still leave lingering questions over the extent of Zardaris own knowledge of the affair. I personally think the resignation of Husain Haqqani will not be enough to resolve this matter, said Siddique-ul-Farooq, a leader of the opposition Pakistan Muslim League-Nawaz (PML-N). The real culprit must be punished. This is a very, very serious matter for the state of Pakistan because the memo compromised the security of a key institution of Pakistan. Analysts warned, the controversy may undermine the relations between Zardari and Pakistans army generals led by General Ashfaq Parvez Kayani, the armys chief of staff, just at a time when the country needs to be united to combat a considerable security challenge thrown up by Taliban militants. I think the element of trust between president Zardari and the army will suffer as we go forward warned Hasan Askari Rizvi, a notable Pakistani commentator. I can see the army keeping a closer watch on president Zardari as they will continue to suspect his moves. Western diplomats who closely track Pakistans domestic political trends cautioned that the controversy unleashed in the wake of Ijazs claim will continue to fuel anti-Zardari popular sentiment. I dont believe, this controversy alone will bring down the president, but I can see how this problem will hang over his head said a Western diplomat in Islamabad who spoke to CBS News on condition of anonymity. President Zardaris opponents will keep on using this case to bring him in more disrepute. People will make this issue look like a case where Zardari tried to stab the army in the back and asked the U.S. for support. The controversy has triggered at a time when Zardaris Pakistan Peoples Party (PPP) faces new domestic political challenges in a country where anti-US sentiment remains strong. Imran Khan, cricket star-turned-politician, in recent weeks has gathered rapidly growing popular support for his Pakistan Tehreek-i-Insaaf (PTI), in the newest challenge to the PPP. Khans main political theme includes a strong anti-US message. As Zardari looses ground and others who are no friends of the US gain ground, the US will have to closely observe Pakistans political trends. This will be very important for the way the US-Pakistan relationship will work in future concluded the diplomat who spoke to CBS News.