What did Moscow say about the lapsing friendship treaty?

What did Russia make of Ukraine's decision to let the Big Treaty lapse? By 27 September 2018, Moscow had already acknowledged, on 25 September, that it had been notified of Kyiv's decision not to renew the Russian–Ukrainian Friendship Treaty.

The Treaty on Friendship, Cooperation, and Partnership between Ukraine and the Russian Federation was signed in 1997. It fixed the principle of strategic partnership, recognised the inviolability of existing borders, respected territorial integrity, and committed each side not to use its territory to harm the other's security.

The decision traced back to the start of the Russo-Ukrainian War in 2014. Ukrainian president Petro Poroshenko signed a decree not to extend the treaty on 19 September 2018, six days before Russia's acknowledgement.

What followed

The treaty expired later, on 31 March 2019, as a consequence of that decision.

The notification and Russia's acknowledgement of it marked a formal step in the process. The treaty had been the basis of the relationship between the two countries since 1997.