Russian President Vladimir Putin warned Thursday of a “global catastrophe” if the Trump administration abandons talks on extending the New START nuclear arms treaty. The agreement—negotiated by the Obama administration in 2010 and ratified by the Senate later that year—limits the total number of deployed nuclear warheads, missiles and bombers. It’s set to expire in 2021, and so far Putin says the U.S. has ignored his efforts to negotiate an extension.

President Vladimir Putin: “No one has spoken with us. No formal process of talks is taking place. And it will all end in 2022.”

In February, the Trump administration withdrew the U.S. from another landmark nuclear deal: the 1987 Intermediate-Range Nuclear Forces Treaty, or INF. The move prompted Russia to withdraw, as well, warning it was preparing a new generation of nuclear-capable missiles.