"The prospects for near-term progress engaging China in a 'trilateral' process are extremely low and given that the Trump administration has not made it clear how it proposes that China can contribute to the process", Kimball said.
He suggested that the US was genuinely seeking a dialogue with China but was also "cynically trying to portray China as an obstacle to nuclear arms reductions when, in reality, it is the United States and Russia that possess 90 percent of the world’s nuclear weapons".
Russia and the US are each estimated to have slightly over 6,000 warheads, while China has 290, France 300, and the UK 200, according to the 2019 figures provided by the US-based Arms Control Association.
Eventually, China and other nuclear powers will need to take greater responsibility for the nuclear disarmament, Kimball added, but right now the US and Russia's best bet is to extend the pact unconditionally for another five years to buy time for talks on a successor deal.
This, Kimball suggested, would "improve the prospects that China might contribute to the disarmament process in the future".
"Without New START, the two largest nuclear arsenals will be unconstrained for the first time in nearly five decades and the risk of a dangerous all-out nuclear arms race will grow", the expert warned.
China has refused to sit down with the US and Russia in Vienna on Monday to discuss the future of the last major arms control pact, the New Strategic Arms Reduction Treaty, which expires in February. Beijing argues it has only a fraction of nuclear arsenals wielded by the two rivals.
