The US president has doubled down on a nuclear testing threat while calling for global denuclearization

US President Donald Trump has defended his push to resume nuclear weapons testing, boasting that America's arsenal is powerful enough "to blow up the world 150 times" and should be maintained through active trials.

In a CBS interview aired on Sunday, Trump was asked why the US needed to test its nuclear weapons again after more than three decades of a Congress-mandated moratorium.

"Because you have to see how they work," Trump replied. "I'm saying that we're going to test nuclear weapons like other countries do. We're the only country that doesn't test, and I don't want to be the only country that doesn't test."

The US last conducted a full-scale nuclear explosion in 1992, and resuming such tests would likely take years and cost hundreds of millions of dollars, according to The Washington Post. US Energy Secretary Chris Wright clarified on Sunday that the testing ordered by Trump would not involve actual nuclear detonations.

"These are what we call non-critical tests," Wright told Fox News, describing them as part of a broader modernization program. "No worries about [a mushroom cloud]," he added, when asked about the possibility of atmospheric or underground blasts.

Despite Trump's claim that Russia and China are secretly conducting tests, both countries' last confirmed nuclear detonations occurred decades ago - Russia's in 1990 and China's in 1996.

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Kremlin spokesman Dmitry Peskov clarified that Russia's recent trials of the Burevestnik nuclear-powered cruise missile and the Poseidon underwater drone did not involve nuclear explosions. President Vladimir Putin has repeatedly stated that Russia would only "act accordingly" if other nuclear powers resumed testing.

China's Foreign Ministry also urged the US to honor its obligations under the Comprehensive Nuclear-Test-Ban Treaty and to maintain the global moratorium on nuclear testing.

Vice President J.D. Vance and several Republican lawmakers have supported Trump's initiative, arguing that non-detonative testing is necessary to ensure the reliability of America's aging nuclear arsenal.

"We have more nuclear weapons than any other country. And I think we should do something about denuclearization," Trump added. "We have enough nuclear weapons to blow up the world 150 times. Russia has a lot of nuclear weapons, and China will have a lot."