"The National Defense Strategy prioritizes major power competition and, in particular, reversing the erosion of US military advantage in relation to China and Russia," Mattis said in prepared testimony to the US House of Representatives Appropriations Subcommittee on Defense on Wednesday.
The combination of rapidly changing technology, the negative impact on military readiness resulting from the longest continuous period of combat in US history, and a prolonged period of unpredictable and insufficient funding, created an overstretched and under-resourced military, Mattis warned.
"[O]ur competitive edge has eroded in every domain of warfare – air, land, sea, space, and cyber… Modernizing the Nation’s nuclear deterrent delivery systems, including our nuclear command and control, is the [Defense] Department’s top priority," Mattis said.
READ MORE: US Needs to Improve Communication with Russia, China — Mattis
The Defense Secretary also stated, that the Trump administration is seeking to expand spending on missile defense to defend the US homeland the FY (fiscal year) 2019 "against an increasingly complex ballistic missile threat".
Mattis also explained that in accordance with the soon-to-be-released 2018 Missile Defense Review, the budget requests capability to keep pace with advancing perils, adding that the budget includes "$12.9 billion for missile defense, including $9.9 billion for the Missile Defense Agency".
On top of that, Mattis urged Congress to permit waivers on sanctions against Russia, Iran, and North Korea in cases where the penalties would adversely affect US national security.
"I look forward to working with Congress to address the national security implications created by this act," Mattis said in reference to a sanctions law known as the Countering American Adversaries Through Sanctions Act (CAATSA). "It is important for us to have a flexible waiver authority, otherwise we prevent ourselves from acting in our own best interest and place an undue burden on our allies or partners."
CAATSA was approved by Congress with a veto-proof majority in 2017 and President Donald Trump reluctantly signed the measure into law.
The law set a January 29, 2019 deadline for the Trump administration to submit a report to Congress on "oligarchs and parastatal entities of the Russian Federation" and the "effects of expanding sanctions to include sovereign debt and derivative products," according to the US State Department.
READ MORE: US Imposes New Sanctions on Russian Entities — Treasury
The Treasury Department subsequently announced sanctions on 19 Russian individuals and five Russian entities, citing attempted interference in US elections through malign cyber activity. The Russian government has repeatedly denied interfering in US elections.