The US official said the expired US-Russia nuclear treaty had "shortcomings," calling for a new agreement to include China.
The US President Donald Trump wants a "better deal," Under Secretary of State for Arms Control Thomas DiNanno told reporters ahead of the meeting at the Conference on Disarmament at UN headquarters in Geneva.
The so-called 'New START' nuclear arms reduction treaty, signed between Moscow and Washington in 2010, limited the number of deployed strategic nuclear warheads for both countries. It expired on Tuesday at 01:00 CET.
The US has long advocated for China's inclusion in future negotiations on nuclear arms control, but Beijing has firmly rejected this proposal.
China's Foreign Ministry spokesperson, Lin Jian, said on Thursday that the country's nuclear capabilities are "on a completely different scale" from those of the US and Russia and that it will not participate in negotiations at this stage.
Currently, the US and Russia hold 80% of the world's nuclear warheads, yet China is rapidly expanding its arsenal.
The New START treaty has also included verification mechanisms.
However, inspections under the treaty were suspended in 2023 following Russia's invasion of Ukraine the previous year, rendering the treaty effectively defunct even before its official expiration.
The lapse has caused global concern, with UN Secretary-General Antonio Guterres calling it a "grave moment for international peace and security."
Guterres urged the US and Russia to quickly agree on a new framework to address the growing arms race.
