Trump Tweets US 'Must Greatly Strengthen' Nuclear Capabilities

PHOTO: President-elect Donald Trump arrives to speak to supporters during a rally, in Grand Rapids, Michigan, Dec. 9, 2016. PlayPaul Sancya/AP Photo
WATCH Donald Trump Surprises With Nuclear Weapons Tweet

President-elect Donald Trump tweeted Thursday that the U.S. "must greatly strengthen and expand" its nuclear capabilities without offering immediate context to what prompted the declaration.

Trump said the expansion and strengthening must happen "until such time as the world comes to its senses regarding nukes."

The Trump transition team did not immediately respond to ABC News' requests for further comment on whether Trump was advocating an expansion of the U.S. nuclear arsenal or modernization, as he had called for on the campaign trail.