During the recent 2022 conflict in Ukraine and the diplomatic talks preceding it, the Russian government kept saying that there were promises made by the US and the west that NATO would not expand eastward, although it was never written down.

Even this recent video (https://www.youtube.com/watch?v=TzgPJeYZaOU) at 3:58 mentions memos and meeting minutes from US archives that say that such an agreement did occur.

So is there any written proof from these archives which can be linked here (other than simply quotes from government officials from the time)?