Some US sources cited in Pakistani media claim Pakistan might have requested/wanted more that it got in the recent $450 million package
Daniel Markey, a senior adviser on South Asia to the Washington-based US Institute of Peace (USIP), described the sale as “a very basic decision, which is more driven by technical necessity to keep the planes flying”. [...]
The Biden administration, he said, was “not going as far as the Pakistan military would have liked”. The Pakistani military, he said, had made a broader request and what was granted would not upgrade or improve the capacity of the F-16s, as it’s basically “a maintenance package”.
I'm not sure how Daniel Markey knows what Pakistan might have requested. So what's the evidence they asked for more?