Did you read the speech or just go with what CNN/twitter/reddit told you to think?
2. He says "We will protect our land with all the forces and means at our disposal and will do everything to ensure the safe life of our people. This is the great liberation mission of our people." The key point here is "our land" - this includes the newly annexed oblasts "all the forces and means at our disposal" - this includes nuclear forces.
In other words he is saying that Russia can use nuclear forces to protect Donetsk / Luhansk / Crima from Ukraine.
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Lavrov won't literally say "if the USA sends one more weapons shipment to Ukraine, we will drop a nuke on every Ukranian troop concentration we can find", because then they would look weak when it turns out they won't do it after all.
This is why all Russia's nuclear threats are veiled and implied. But make no mistake, they are there, and the message one can read between the lines is put there intentionally. It might be an empty threat or it isn't, but a threat it certainly is.
There are certainly concrete and non-ambiguous threats made behind the scenes, making explicit what actions each party is willing to commit to, but those don't end up in the media.
Such as “escorting” warplanes away from borders or being caught spying on sensitive military installations/procedures.
No nuke, so far.