"I have requested PM Gilani to accept my resignation as Pakistan Ambasssador to US," Haqqani tweeted from Pakistan, where he has returned to answer allegations that he colluded with Pakistani-American businessman Mansoor Ijaz to draft a May 10 memo to then Joint Chiefs Chairman Adm. Mike Mullen that offered to revamp Pakistan's national security leadership in exchange for US support to prevent a purported military coup. "I have much to contribute to building a new Pakistan free of bigotry & intolerance. Will focus energies on that," Haqqani tweeted. Haqqani had offered to resign last week as Ijaz publicly accused him of engineering the memo, which contained an offer to clean house of elements within the military and intelligence agencies that allegedly support militancy. The unsigned memo requested that Mullen send an urgent message to Pakistan's military and intelligence to scuttle their plans to take down Pakistan's civilian government, led by President Zardari.