The 50-member House Committee on International Relations, headed by Republican chairman Henry Hyde, was due to hear John Hillen, the State Department's Assistant Secretary for Political-Military Affairs, on Thursday on the deal notified by the Pentagon on June 28.
Unless stopped by Congress within 30 days, Pakistan will get 36 new F-16C/D fighter aircraft, 200 sidewinder missiles, 200 air-to-air missiles, 500 kits for ground-attack satellite-guided bombs and 36 advanced pilot helmets that can display targeting information on the visor.
No reason was given for the postponement of the House panel hearing "until further notice" and there is no word yet about when the 18-member Senate Foreign Relations Committee would meet to review the deal.
But reports suggest that some lawmakers have raised objections to the Bush administration's bid to push America's largest arms deal with Islamabad without due consultations with the US Congress.
Pakistan Foreign Minister Khurshid Mehmood Kasuri himself told the media during his just concluded visit that the administration had apprised him of objections raised by some Congressman, but it had also assured that this would not pose a major hurdle in its eventual approval.
Among other things, legislators are concerned about how Pakistan intends to ensure that its long-time ally China will not have access to advanced US technology and whether there has been any diversion of such technology already in Pakistani hands.
Also complicating the matter is a new report by Congressional Research Service, Congress's analytical arm, that the single-engine Block 50/52 Falcon being sold to Pakistan is the most modern F-16 flown by the United States and may be better suited to air-to-air combat against India than fighting terrorists.
Joseph Crowley, a Democratic member of the House panel from New York, for one has expressed deep concern "about the process or the lack thereof" that the administration used to inform Congress about the F-16 deal with Pakistan.
He is also concerned that Pakistan has not moved forward with promises of democracy, fighting its internal extremists, enforcing human rights, or respecting minorities.
It has also not let US interrogators to question the father of Pakistan's atomic bomb, Abdul Qader Khan, accused of running a private nuclear Wal-Mart.
Kasuri told reporters in Washington on Tuesday that it was not easy to "get hold of this man", considered a national hero in Pakistan, who even nurtured presidential ambitions.
But Khan had been made to confess his sins of nuclear proliferation in public. He had been humiliated and disgraced in what the opposition called under US pressure. "And you say he has been let off with just a rap on the knuckles!" Kasuri told a questioner.
Islamabad was also providing all the information sought by US.
It was also cooperating with the International Atomic Energy Agency (IAEA) though it was not required to do so as a non-signatory of the Non-Proliferation Treaty (NPT).
The administration may still win approval for the deal as claimed by Kasuri, but a public debate over the sale could prove awkward for the administration and Pakistan.
A previous F-16 sale was halted in 1990 because of concerns over Pakistan's nuclear programme.