The US and Japan are sponsoring a UN security council resolution calling on all nations not to deploy or develop nuclear weapons in space, the US ambassador has announced.

Linda Thomas-Greenfield told a UN security council meeting that “any placement of nuclear weapons into orbit around the Earth would be unprecedented, dangerous, and unacceptable.”

The announcement follows confirmation from the White House last month that Russia has obtained a “troubling” anti-satellite weapon capability, although such a weapon is not operational yet.

Russian President Vladimir Putin declared later that Moscow has no intention of deploying nuclear weapons in space, claiming that the country has only developed space capabilities similar to those of the US.

The Outer Space Treaty ratified by about 114 countries including the US and Russia prohibits the deployment of “nuclear weapons or any other kinds of weapons of mass destruction” in orbit or the stationing of “weapons in outer space in any other manner.”

Japan’s foreign minister, Yoko Kamikawa, who chaired the council meeting, said that even during “the confrontational environment” of the cold war, global rivals agreed to ensure that outer space remained peaceful. That prohibition on putting any weapons of mass destruction into orbit must be upheld today, she said.

Thomas-Greenfield said all parties to the treaty must commit to the ban on nuclear and other destructive weapons, “and we must urge all member states who are not yet party to it to accede to it without delay.”

Thomas-Greenfield also reiterated to the council that the US is willing to engage with Russia and China, without preconditions, on bilateral arms control issues.

In February, the White House said a new Russian anti-satellite weapon was being monitored, but was not an immediate threat to anyone’s safety. A spokesperson did not confirm or deny reports that the new weapon was nuclear, but did say it was “space-based” and that it violated the 1967 Outer Space Treaty, which prohibits the deployment in space of nuclear weapons or other weapons of mass destruction.

Monday’s proposed resolution from the US and Japan was condemned as “yet another propaganda stunt by Washington,” “very politicised” and “divorced from reality” by Russia’s deputy US ambassador Dmitry Polyansky.

He criticised the text, saying the wording had not been worked out by experts nor discussed at specialised international platforms such as the UN Conference on Disarmament or the UN Committee on Outer Space.

UN secretary-general António Guterres briefed the council, saying “geopolitical tensions and mistrust have escalated the risk of nuclear warfare to its highest point in decades.”

He said the movie Oppenheimer about Robert Oppenheimer, who directed the US project during the second world war that developed the atomic bomb, “brought the harsh reality of nuclear doomsday to vivid life for millions around the world.”

“Humanity cannot survive a sequel to Oppenheimer,” the UN chief said.

The Associated Press contributed to this report