WASHINGTON: For the second time in six months, the US has issued a waiver for sale of major defence equipment to Pakistan likely to be worth over $2 billion, citing national security interests.The waiver issued quietly by the then Deputy Secretary of States Thomas Nides on February 15 and posted on the State Department website a week later on February 22 would pave the way for some major defence equipment sales to Pakistan.In September last year, the US had waived conditions that would have halted $2 billion in aid to Pakistan, which was slammed for not making progress in fighting terrorism.Pakistan has received $7.9 billion worth of military equipment from the US since 2001.A State Department spokesperson said, "The Department issued the waiver because we have determined that security assistance is important to the national security interests of the United States and is a critical component of US efforts to continue to build a strong, mutually beneficial relationship with Pakistan grounded in concrete action on areas of shared interest."The waiver, issued within a fortnight of Secretary of State John Kerry taking the reins US diplomacy on February 1, allows for the execution of America's Foreign Military Financing (FMF) programme, and for the sale or export of certain Major Defence Equipment (MDE)."Major Defence Equipment," means any US manufactured defence article whose export is controlled by US Munitions List which has a nonrecurring research and development cost of more than $50,000,000 or a total production cost of more than $200,000,000. These items require Congressional notification, the spokesman said."As a matter of policy we do not discuss proposed defence sales or transfers until they have been formally notified to Congress ," he said, refraining to give any figure to the expected sale of major defence items to Pakistan after this waiver.In July, 2011, the Obama administration had decided to suspend $800 million in aid to the Pakistan's military signallling a tougher US line.Washington had made it clear soon thereafter that it will not lift the hold on its military aid to Pakistan, reiterating that Islamabad needs to takes steps in the war against terror