In CNN's April 15, 2022 He was once Putin's Prime Minister. Now he supports Ukraine after
05:30 former Russian Prime Minister Mikhail Kasyanov says (my transcription, no closed captions available):
I'll bring you back twenty years ago when I was prime minister and (Putin) was in (his) first term as president. At that time we had excellent relations with the United States (unclear) in general. At that time me -- as the head of the cabinet -- I announced (that) I was dreaming to get Russia as a full-fledged member of NATO.
Mr. Putin at that time, in not such a direct way also said that he didn't exclude such a position. And we established together with NATO a special council - a Russia-NATO Council, and relations were very good.
Right now it's a completely different situation (and) a completely different Putin.
Wikipedia's Russia-NATO relations: NATO-Russia Council doesn't specifically mention any discussion of Russia joining NATO. So I'd like to ask:
Question: Did Russia once want to join NATO? Does former Russian Prime Minister Mikhail Kasyanov refer to a serious interest in the past?
Note: I'm asking about Russia's past intention1, not Kasyanov's.
Here's a second reference to this possibility. In CNN's May 16 2022 Tony Blair explains what he thinks changed Putin (my transcription):
The trajectory has been away from the reforming, western-oriented leader who could have allowed Russia to become part of the west - people used to even talk in the old days (I'm talking times when I was there) people were even talking about 'could Russia become a member of the European Union? Was there a way that Russia could be accommodated literally within the structures of NATO?'
And it's very important that people remember this because this myth that Putin perpetrates that we were somehow trying to push him and humiliate Russia... Russia's problem is not the result of our humiliation of Russia, it's the result of bad government in Russia.
Of course "people were even talking about" is not evidence of Russia's serious interest, but it at least supports the question's premise that it is valid to ask the question if it did.
1Answers should reference statements by and evidence of actions associated with Russia itself, not Kasyanov "dream". See this answer in meta.