President-elect Donald Trump caused alarm during the campaign with his talk about nuclear weapons. | AP Photo Trump pledges to 'expand' U.S. nuclear capability

President-elect Donald Trump on Thursday called on the U.S. to “greatly strengthen and expand its nuclear capability,” a move that would match Vladimir Putin's plans to expand Russia's arsenal — even as it upends longstanding U.S. nonproliferation policy.

“The United States must greatly strengthen and expand its nuclear capability until such time as the world comes to its senses regarding nukes,” Trump tweeted Thursday.


His comments followed remarks from Putin, the Russian strongman, who called on his country to “strengthen” its nuclear forces.

“We need to strengthen the military potential of strategic nuclear forces, especially with missile complexes that can reliably penetrate any existing and prospective missile defense systems,” he said, according to multiple news reports.

In a speech recounting Russia’s military activities over the past year, Putin said while his army’s preparedness has “considerably increased,” according to reports, it also must improve to ensure it can “neutralize any military threat.”

“We must carefully monitor any changes in the balance of power and in the political-military situation in the world, especially along Russian borders, and quickly adapt plans for neutralizing threats to our country,” he said.

Trump’s tweet provided no further context. In fact, he had tweeted just nine minutes earlier that former House Speaker Newt Gingrich “incorrectly stated” that his mantra to ‘DRAIN THE SWAMP’ was no longer being used.”

“Actually, we will always be trying to” drain the swamp, Trump said.

But his message to expand America’s nuclear capability goes against decades of policy to reduce the stockpile of nuclear warheads and could potentially violate an arms control treaty with Russia. The U.S. has a stockpile of roughly 4,500 nuclear warheads and nearly 1,500 deployed warheads (Russia’s armaments are nearly identical, as both nations account for more than 90 percent of the world’s nuclear warheads.)

The U.S. and Russia are due to meet nuclear reduction targets by February 2018 under the New START Treaty, which can be extended for another five years in 2021.

Trump’s comments on the U.S. nuclear arsenal also came after he met with a half-dozen top military officers Wednesday afternoon at Mar-a-Lago, his Florida resort where he’s staying for the holidays.

While Trump spoke with the top Pentagon brass about costs of major contracts, including the F-35, it’s not clear if they also discussed nuclear matters — or its cost, either.

John Tierney, a former Democratic congressman and current executive director of the Center for Arms Control and Non-Proliferation, cast Trump’s tweet as perilous.

“It is dangerous for the President-elect to use just 140 characters and announce a major change in U.S. nuclear weapons policy, which is nuanced, complex, and affects every single person on this planet,” he said in a statement, warning that an expansion threatens a nuclear arms race.

“The potential consequences of changing U.S. nuclear weapons policy so drastically are simply unimaginable,” he warned. “Current plans already call for spending $1 trillion over the next three decades to modernize and maintain the U.S. nuclear arsenal, which the Pentagon has expressed concern about being able to afford. The President-elect will have to explain why any increase is necessary both financially and strategically.”

But Jason Miller, a Trump spokesman, said the president-elect was talking about expanding nonproliferation efforts. "President-elect Trump was referring to the threat of nuclear proliferation and the critical need to prevent it — particularly to and among terrorist organizations and unstable and rogue regimes," Miller said in a statement. "He has also emphasized the need to improve and modernize our deterrent capability as a vital way to pursue peace through strength.”

Trump’s casual talk during the campaign about nuclear weapons was alarming to many, particularly his suggestion that other countries — including Japan, South Korea and Saudi Arabia — should be allowed to develop them.

But he also told The New York Times in March that “it’s a very scary nuclear world.”

“Biggest problem, to me, in the world, is nuclear, and proliferation,” Trump said at the time.