He broadly described the USA strategy's approach to arm control as worrying, including its silence on whether the US wants to exercise an option in the New START treaty to extend its terms for five years.
Secretary of Defense James Mattis has said that a plan to add a new cruise missile to the United States' nuclear arsenal aims to provide additional leverage to US negotiators trying to persuade Russian Federation to stop violating a key arms control treaty.
Mattis suggested that the two new weapons, the SCLM in particular, could be used as bargaining chips to convince Russian Federation to abandon its own low-yield weapons programs and comply with the Intermediate-Range Nuclear Forces Treaty (INF).
"As you know, we have an ongoing issue with Russia's violation of the INF".
"I don't think there is any such thing as a 'tactical nuclear weapon, '" he said.
"I want to make sure that our negotiators have something to negotiate with", Mattis said. "But again, we have to deal with where we're at today". "And in that regard, I believe we have to give our negotiators something with which to negotiate".
Mattis explained that Congress "rightfully mandated" the National Defense Strategy but then entered a government shutdown, forcing the military to operate under a "disruptive continuing resolution". The latest temporary funding measure expires at midnight Thursday.
Mattis appeared alongside Gen. Paul J. Selva, vice chairman of the Joint Chiefs of Staff.
The U.S. retired its previous nuclear-tipped, sub-launched cruise missile - the nuclear Tomahawk land-attack cruise missile (TLAM/N) and its W80-0 warhead - sometime between 2010 and 2013.
The new US posture focuses heavily on what the administration sees as an overdue modernization of the nuclear arsenal. The Foreign Ministry said Russian Federation is well within the treaty's limitations of 1,550 strategy nuclear warheads and 700 deployed launchers.
In his prepared remarks, Mattis said that under the new NPR, the first since 2010, the US "remains committed to its global leadership role to reduce the number of nuclear weapons, and to fulfill existing treaty and arms control obligations".
Congress has failed to pass a budget for the fiscal year that began last October 1.
"A review of the global nuclear situation is sobering", Mattis said.
It particularly condemned the development of low-yield nuclear weapons, which Moscow said can significantly lower the threshold for the use of nuclear weapons and "lead to a nuclear-missile war even in low-intensity conflicts".
"China, too, is modernizing and expanding its already considerable nuclear forces, pursuing entirely new nuclear capabilities", he said, and "is also modernizing its conventional military to challenge USA military superiority". He warns of growing competition and threats from China, Russia, North Korea, Iran and extremist organizations.
It remains to be seen whether and when Congress will appropriate funds for the new capabilities the Pentagon outlined in last week's nuclear weapons policy.