Regulatory Query on Analytical Methods

Currently I am transferring a method from one site to another but am having difficulty completing the transfer. The expert site I am transferring from is currently releasing the drug product being transferred to the U.S. so I am concerned now I will put a question mark over this method and potentially stop this release.

My query is when methods are submitted for approval by a site, what do FDA give back to confirm they are ok with the method, because obviously the expert site must have had the method validation and method reviewed and approved by the FDA before allowing release of the product into the U.S.

I know in the E.U. for API they have CEPs. Is there some similar document out there for Drug Products being released into the U.S. Hope that makes sense