The U.S. is currently behind China and Russia in the development and deployment of hypersonic weapons and will deliver strike and layer-hypersonic defence capability in the early- to mid-2020s, a top Pentagon official has said.

“For more than a decade, these great-power competitors (China and Russia) have been rapidly developing highly capable systems that challenge our domain dominance on the tactical battlefield," the principal director for hypersonics in the Office of the Undersecretary of Defence for Research and Engineering said in a Pentagon release.

China and Russia have fielded high-end, integrated air-missile defence systems to challenge U.S. aircraft out hundreds of miles. Their anti-satellite systems aim to degrade our capabilities in space and on land, and their attack cruise, ballistic and hypersonic missiles put our troops, ports and airfields at risk, he said. These systems, White noted, present a significant challenge to traditional U.S. weapon systems.

He said that the adversaries have increasingly focused on systems that dramatically compress the timelines and the timescale of a tactical battlefield. These systems — including ballistic missiles, ballistic missiles with manoeuvring re-entry vehicles, and vehicles that are increasingly hypersonic in nature — give adversaries the ability to hold our forces at risk from hundreds, even thousands, of miles away, with flight times that are measured in minutes.

Conversely, the United States' portfolio of traditional, tactical strike weapons includes sea-launched subsonic cruise missiles, air-launched subsonic cruise missiles, and platforms to deliver those air-launched subsonic cruise missiles that are either subsonic or, at best, low supersonic, he said.

"These systems will take on the order of 10 times longer to fly long-range strike missions when compared to the adversary's high-speed systems," White said. "It presents a battlefield asymmetry and timescale that we simply cannot allow to stand."

To address these challenges, DOD developed the Hypersonics Modernization Strategy that accelerates the development and delivery of transformational warfighting capabilities based on hypersonic systems, he said.

"This strategy consists of long-range responsive strike against time-critical, high-value targets where we are fielding a family of air-, land- and sea-launch, conventionally armed hypersonic strike weapons," White said. "These weapons will be designed for defeat of maritime coastal and inland targets of critical importance on a timescale of relevance for the tactical battlefield. To defend against [an] adversary['s] hypersonic weapons, we are delivering a comprehensive layer-defeat strategy that applies kinetic and non-kinetic capabilities to deny, degrade and defeat those weapons at every possible point in their kill chain. Technologies will also be developed to mature reusable hypersonic systems for future application to time-critical penetrating [intelligence, surveillance, and reconnaissance] and strike missions."

DOD's strategy is being put in place in a coordinated set of programs across the military services and agencies. The Office of the Secretary of Defence, Army, Navy, Air Force, Missile Defence Agency, Defence Advanced Research Projects Agency, Space Development Agency and the Strategic Capabilities Office are working to develop capabilities throughout the multiple phases of this strategy, he said.