A number of UNSCRs, such as 2231 and 1929, use the MTCR Annex as a standard for determining legitimate missile-related transfers concerning Iran.
But a November letter from Russia to the UNSG makes clear Moscow’s view of the MTCR’s appropriate role in UNSCRs:
We continue to view with regret the ongoing attempts by certain Member States to distort the nature and scope of the Missile Technology Control Regime (MTCR), which is obviously viewed by them not as an informal political understanding between 35 States on export control issues, but as a kind of “universal legally binding instrument” that somehow prohibits all countries in the world, apart from themselves, to develop any space capabilities at all. Moreover, by making such flawed logic, these Member States are accusing by extension all other non-nuclear weapons States that are developing their own missile and space programmes of effectively designing delivery systems capable of carrying nuclear weapons.
In this context we would like to reiterate that the category I parameters of the MTCR annex are nothing but a reference tool for exporting States and were never intended to be used in the context of resolution 2231 (2015) to ascertain whether or not certain ballistic missiles are designed to be capable of carrying nuclear weapons.