US President-elect Donald Trump called on Thursday for a strengthening of America’s nuclear weapons programme, throwing into doubt longstanding efforts to reduce its arsenal.



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

It was unclear what prompted the comment on a medium that favours brevity over context. But it came on the same day that also President Vladimir Putin addressed Russia’s nuclear capacity.

“We need to strengthen the military potential of strategic nuclear forces, especially with missile complexes that can reliably penetrate any existing and prospective missile defence systems,” Putin said.

Trump spokesman Jason Miller later issued a statement to NBC News, which did not add much clarity.

Miller referred “to the threat of nuclear proliferation and the critical need to prevent it, particularly to and among terrorist organizations and unstable and rogue regimes”.

Trump, Miller said, “has also emphasized the need to improve and modernize our deterrent capability as a vital way to pursue peace through strength”. Asked if this meant Trump was not in fact calling for more nuclear weapons, NBC reported, Miller did not respond.

There are more than 15,000 nuclear weapons in the world, over 90% of which are in the US and Russia. Since the end of the cold war, the old rivals have worked to curtail production and then cut their nuclear stockpiles.

But relations have deteriorated significantly in recent years, while Trump’s freewheeling election campaign has shaken up many former certainties. In May, he suggested he could support South Korea, Japan and Saudi Arabia arming themselves with nuclear weapons for their own defence. “It’s going to happen anyway,” he told CNN. “It’s only a question of time.”

In a Republican primary debate, Trump seemed stumped by a straightforward question about the nuclear triad. And in a presidential debate, he appeared to contradict himself over the policy of first use, eventually saying: “I can’t take anything off the table.”

During the campaign, Hillary Clinton hammered him as too erratic and volatile, saying more than once: “A man you can bait with a tweet is not a man we can trust with nuclear weapons.” Ten former nuclear missile launch operators also wrote that Trump lacks the temperament and diplomatic skill to avoid nuclear war.

On Thursday the state department declined to comment on whether Trump’s tweet called his temperament into question. “Not for me to say,” spokesperson John Kirby said. “I can’t speak for the president-elect’s nuclear views or policy going forward.”

Kirby was not aware of any countries expressing concern over the tweet, he added.

Trump’s transition website says he “recognizes the uniquely catastrophic threats posed by nuclear weapons and cyberattacks”, adding that he will modernise the nuclear arsenal “to ensure it continues to be an effective deterrent”.



But his latest statement appears to put him, once again, at odds with Barack Obama, who in a speech in Prague in 2009 outlined an aspiration for a planet without nuclear weapons while acknowledging it might not happen in his lifetime.

Obama has trumpeted the Iran nuclear deal but in April this year told his final nuclear security summit in Washington that terrorist “madmen” obtaining and using a nuclear weapon is one of the greatest threats to global security. Fifty world leaders attended but Putin was not among them.

Trump, who is at his Mar-a-Lago resort in Florida for the holidays, met incoming White House national security adviser Michael Flynn on Wednesday, along with a dozen Pentagon officials involved with defence acquisition programmes and chief executives of Lockheed Martin and Boeing, the country’s two biggest defence contractors.

US ballistic missile submarines, bombers, and land-based missiles – the nuclear triad – are expected to reach the end of their useful lives over the next decade. Maintaining and modernising the arsenal is expected to cost about $1tn over 30 years.