Recurring pro-Kremlin disinformation narrative that NATO had promised Russia it would not expand to the East.
NATO allies take decisions by consensus and these are recorded. There is no record of any decision taken by NATO about putting a halt to enlargement to the East. Personal assurances from individual leaders cannot replace Alliance consensus and do not constitute formal NATO agreements. Moreover, at the time of the alleged promise, the Warsaw Pact still existed, which by definition precluded any member of the Pact from joining NATO. Its members did not agree on its dissolution until 1991. This was confirmed by Mikhail Gorbachev himself in an interview with Russia Beyond the Headlines:
“The topic of 'NATO expansion' was not discussed at all, and it was not brought up in those years. I say this with full responsibility. Not a single Eastern European country raised the issue, not even after the Warsaw Pact ceased to exist in 1991. Western leaders did not bring it up either”.
Central and Eastern European countries began seeking NATO membership in the early 1990s. NATO actively sought to create a cooperative environment that was conducive to enlargement while simultaneously building special relations with Russia.
Also, NATO does not "expand" in the imperialistic sense as described by pro-Kremlin media. Rather, it considers the applications of candidate countries who want to join the Alliance based on their own national will. NATO enlargement is not directed against Russia.
See similar cases claiming that Gorbachev was promised that NATO would not “expand eastwards” and that the expansion of NATO to the East is military aggression.