A senior Russian official voiced concerns on Monday that Washington is increasing the role of nuclear weapons in its military planning as part of a stepped-up campaign by the Trump administration to ensure “U.S. military superiority over the rest of the world,” while he also denied U.S. allegations that Moscow has violated an arms treaty.

Andrei Belousov, deputy director of the Foreign Ministry’s Department of Nonproliferation and Arms Control, told the U.N. General Assembly’s disarmament committee that Russia is “especially concerned” at the Trump administration’s Nuclear Posture Review.

The policy review, released in early February, provides for “the creation of low-yield nuclear weapons that would lower the threshold of the use of nuclear weapons,” Mr. Belousov said. He said it “also envisages a return to the concept of a ‘limited nuclear war.’”

“In essence, the U.S. military thinking in [the] nuclear field has rolled back a half a century when it was believed that a nuclear war was admissible and could be won,” he told the committee’s session on nuclear weapons.

Mr. Belousov said Russia has repeatedly called for “appropriate conditions that would allow us to take practical measures to free the world from nuclear weapons.” But he said Moscow must take into account “the existing strategic realities.”