Arms control talks between the United States and Russia began in Vienna on Monday. The US envoy has made clear they will be about nuclear weapons, suggesting they will include replacing the New Strategic Arms Reduction Treaty (START), which expires in February.

“We’ll see,” US special presidential envoy for arms control Marshall Billingslea told Reuters as he arrived with his delegation at a palace adjoining Austria’s Foreign Ministry. He declined to elaborate on their content. Russian Deputy Foreign Minister Sergey Ryabkov was quoted as telling reporters: “Let’s see, let’s see. We are always very hopeful.”

New START imposes the last remaining limits on US and Russian deployments of strategic nuclear arms to no more than 1,550 each. It can be extended for up to five years if both sides agree to.

US President Donald Trump has repeatedly called for China to join the US and Russia in talks on an agreement to replace New START. Chinese Foreign Ministry’s spokesperson Zhao Lijian has said that Washington’s attempts to engage Beijing in Russian-US talks on nuclear weapons were absurd, because Washington is constantly seeking to violate its commitments under the existing agreement, TASS reported.