During a national-security forum on Monday, Work said that China and Russia are heavily investing in a roboticized army, according to a report from Defense One.

"We know that China is already investing heavily in robotics and autonomy and the Russian Chief of General Staff [Valery Vasilevich] Gerasimov recently said that the Russian military is preparing to fight on a roboticized battlefield," Work said at the forum, hosted by the Center for a New American Security in Washington, DC.

"[Gerasimov] said, and I quote, 'In the near future, it is possible that a complete roboticized unit will be created capable of independently conducting military operations,'" Work continued.

Work then said it's important for the US to "dominate" machine learning and artificial intelligence to offset the imposing threats posed by China and Russia.

Concerns over the creation of killer robots have mounted as advancements have been made in the field of artificial intelligence. More than a thousand artificial-intelligence researchers cosigned an open letter calling for a ban on autonomous weapons this summer, including big names like Tesla CEO Elon Musk and scientist Stephen Hawking.