As of September 2020, the State Department said the active US stockpile consists of 3,750 warheads. The US also has approximately 2,000 retired warheads waiting to be dismantled, bringing the total stockpile to about 5,750 warheads.
The last time the US government disclosed the size of its stockpile was in 2018. The Trump administration stopped releasing the numbers after that, drawing criticism from arms control advocates over the lack of transparency.
The State Department said that since fiscal years 1994 through 2020, the US has dismantled 11,683 nuclear warheads. And since September 2017, the US has dismantled 711 warheads.
The disclosure comes as the US and Russia are engaging in nuclear arms control talks. Senior US and Russian diplomats met in Geneva last week and agreed to establish two working groups to discuss a way forward on arms control and strategic stability.
The New START is the last nuclear arms control treaty between the US and Russia. President Biden and President Putin agreed to extend the treaty for five years at the beginning of the year.
According to the Arms Control Association, as of January 2020, Russia had 6,375 warheads. Of that number, 4,315 nuclear warheads were active, and 2,060 were retired and awaiting dismantlement.