“We are just thinking about it. They weren’t shy to openly talk about it during the past years,” Putin said, referring to the U.S. policy, as he attended a summit in Kyrgyzstan of a Moscow-dominated economic alliance of ex-Soviet nations.

For years, the Kremlin has expressed concern about U.S. efforts to develop the so-called Conventional Prompt Global Strike capability that envisions hitting an adversary’s strategic targets with precision-guided conventional weapons anywhere in the world within one hour.

“Speaking about a disarming strike, maybe it’s worth thinking about adopting the ideas developed by our U.S. counterparts, their ideas of ensuring their security,” Putin said with a thin smile, noting that such a preemptive strike was intended to knock out command facilities.

He claimed that Russia already has commissioned hypersonic weapons capable of carrying out such a strike, while the U.S. hasn’t yet deployed them. He also claimed that Russia now has cruise missiles that surpass their U.S. equivalents.

While Putin appeared to refer to conventional precision-guided weapons when he talked about possibly mimicking the U.S. strategy, he specifically noted that the U.S. hasn’t ruled out the first use of nuclear weapons.

“If the potential adversary believes that it can use the theory of a preemptive strike and we don’t, it makes us think about the threats posed by such ideas in other countries’ defensive posture,” he said.

In Washington, advisers to President Joe Biden viewed Putin’s comments as “saber-rattling” and another veiled warning that he could deploy a tactical nuclear weapon, according to a U.S. official who was not authorized to comment and spoke on the condition of the anonymity.

The official noted that Russian military doctrine has long stated that Moscow reserves the right to first use of a nuclear weapon in response to large scale military aggression.

John Erath, senior policy director for the Center for Arms Control and Non-Proliferation, also viewed Putin’s statement as yet another attempt to raise the nuclear threat.

“He doesn’t quite say we’re going to launch nuclear weapons, but he wants the dialogue in the U.S. and Europe to be, ’The longer this war goes on, the greater the threat of nuclear weapons might be used,’” Erath said.

Putin was asked Wednesday at a Kremlin conference whether Russia could commit to forswearing a first strike and responded that such an obligation might prevent Russia from tapping its nuclear arsenal even if it came under a nuclear attack.

“If it doesn’t use it first under any circumstances, it means that it won’t be the second to use it either, because the possibility of using it in case of a nuclear strike on our territory will be sharply limited,” he responded.