Really, that is the question you have. According to 2015 data, Pakistan export to US is only $3.5 billion, marginal amount, given size of Pakistan economy. So, there should not be much impact that Pakistan can not manage easily.
Pakistan has virtually no dependence on US aid or investment, that also gives free hand to Pakistan.
Military equipment wise, Pakistan had been living through de facto US sanction and using alternative for years now and should not be issue on that front either.
So anyone raising specter over "US sanction" on Pakistan, is just pointless fear or fear mongering.