He said that Russia is "trying to expand its strategic nuclear arsenal to deal with the United States."

“Therefore, as people talk about a new strategic nuclear arms reduction treaty, we say - listen, if there will be an extension of the START treaty, we must ensure that it includes all the new weapons that Russia wants to get,” said Esper .

In early July, Russian leader Vladimir Putin announced that START III would expire in early 2021.

He noted that Moscow still does not see Washington’s readiness to discuss the extension of START III or the development of a new agreement.