Russia’s parliament completed the passage of a law on Wednesday withdrawing ratification of the global treaty banning nuclear weapons tests, evidence of the deep chill in relations with the United States as Moscow pursues its war in Ukraine.

Deputy Foreign Minister Sergei Ryabkov said Russia was not prepared to resume discussing nuclear issues with the U.S. unless Washington dropped its “hostile” policy.

The bill to deratify the Comprehensive Nuclear Test Ban Treaty (CTBT) was approved by 156 votes to zero in the upper house after the lower house also passed it unanimously. It now goes to President Vladimir Putin for signing.

Putin had requested the change to “mirror” the position of the United States, which signed the CTBT in 1996 but never ratified it.

Though it has never formally come into force, the CTBT has made nuclear testing a taboo – no country except North Korea has conducted a test involving a nuclear explosion this century.

Russia says it will not resume testing unless Washington does, but arms control experts say a test by either Russia or the United States could trigger a new arms race – and more testing by other countries – at a moment of acute tension, with wars raging in Ukraine and the Middle East.

CNN published satellite images last month showing that Russia, the United States and China have all expanded their nuclear test sites in recent years.

The U.S. Energy Department said last week it had conducted a chemical explosion at its test site in Nevada “to improve the United States’ ability to detect low-yield nuclear explosions around the world”.

Speaking to Russian lawmakers before Wednesday’s vote, deputy foreign minister Sergei Ryabkov said the Nevada blast was “undoubtedly a political signal”.

“As our president said, we must be on alert, and if the United States moves towards the start of nuclear tests, we will have to respond here in the same way,” he said.

Russia says its monitoring stations will keep supplying data to the global network that detects nuclear blasts.

But In separate comments, RIA news agency quoted Ryabkov as saying Russia was not ready to resume nuclear talks with the U.S.

Without changes in its “deeply fundamental hostile course”, he said, “a return to dialogue on strategic stability, including the topic of strategic offensive arms and other topics in the form that was previously practised, is simply impossible”.

Russia accuses Washington of trying to inflict a “strategic defeat” on it by arming Ukraine in the war. The U.S. says it is helping Kyiv to defend itself.

The absence of nuclear dialogue has called into question the fate of the New START treaty, which limits the number of strategic warheads that Russia and the U.S. can deploy.

Russia suspended the treaty this year and it is due to expire in 2026, leaving the two countries without any remaining bilateral nuclear weapons agreement.

Ryabkov said Moscow had received an unofficial memo from Washington on arms control and was looking at it, but it had “no novel elements”.

According to the Pentagon’s latest report on China’s military, China has launched its first nuclear-powered guided missile submarines, giving it land and sea attack options that were previously limited to US and Russian vessels.

The Pentagon report, released on October 20, provides the first clear confirmation that the modified submarines seen in Chinese shipyards over the last 18 months are Type 093B guided missile submarines.

According to Reuters, satellite images from the Huludao shipyard in northeast China showed a new or upgraded class of submarine, possibly with vertical tubes for launching cruise missiles, in May 2022.

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The Pentagon report says that in the short term, the Chinese navy “will have the ability to conduct long-range precision strikes against land targets from its submarine and surface combatants using land-attack cruise missiles, notably enhancing (China’s) power projection capability”.

Known as SSGNs, conventionally armed missile submarines were developed by the Soviet Union during the Cold War in part to target U.S. aircraft carriers, while the U.S. Navy developed its own version by converting ballistic missile boats to carry large numbers of land-attack Tomahawk cruise missiles.

Cruise missiles are typically long-range, precision weapons that, unlike ballistic weapons, fly at low altitudes or skim the surface of the sea.

The submarine USS Florida fired 93 Tomahawks against Libyan air defences in 2011 – the first combat strikes from a U.S. SSGN and an event that regional military attaches say was closely studied by Chinese strategists.

Some analysts say the PLA navy will be eager to deploy the vessels as an extra weapon against aircraft carriers as well as a land-attack platform, allowing strikes from a far greater range than its fleets of smaller attack submarines.

The report notes that three of the new SSGNs could be operational by next year, as part of a wider expansion of its submarine fleet – both nuclear and diesel powered – which could number 65 vessels in 2025.

The Chinese defence ministry did not respond to questions from Reuters.

The confirmation comes amid an intensifying submarine arms race as China constructs a new generation of nuclear-armed boats as part of its evolving deterrent force.

The effort to track China’s submarines at sea is one of the core drivers of increased deployments and contingency planning by the U.S. Navy and other militaries across the Indo-Pacific region.

Singapore-based security scholar Collin Koh said the SSGNs were an important new capability for the Chinese navy.

With an expected core armament of cruise missiles, “this potentially allows them to carry out saturated land and anti-ship attacks at standoff range”, he said, which would complicate strategic calculations by China’s rivals.

“I would also expect the Chinese have learned from the Russian experience in using them to threaten U.S. aircraft carriers – with an SSGN, you can launch strikes at standoff range, unlike a typical attack submarine that could have more limited weapon options, and that is a real advantage,” said Koh, of the S. Rajaratnam School of International Studies.

Research discussed at the U.S. Naval War College in May noted that the PLA was close to breakthroughs in making its nuclear-powered submarines far quieter and more difficult for the U.S. and its allies to track.

Some diplomats and analysts said, however, that it was unclear whether those breakthroughs had been incorporated into the recently launched SSGNs. The upgrades are expected in nuclear-powered boats launched before the end of the decade.

“Unless they are certain of improvements, we can expect the PLA navy to be cautious in how they initially deploy them,” said an Asian military attache who is tracking China’s submarine force. The attache declined to be named because of the sensitivity of the matter. “But we know the submarine force is a priority for Xi Jinping, and this is one more sign they are getting there.”