US President-elect Donald Trump has called for the country to expand its nuclear weapons capabilities until the world "comes to its senses" - a signal he may support costly efforts to modernise the aging US nuclear arsenal.

During the next decade, US ballistic missile submarines, bombers, and land-based missiles - the three legs of the nuclear triad - are expected to reach the end of their useful lives.

Maintaining and modernising the arsenal is expected to cost about $1 trillion dollars over 30 years, according to independent estimates.

Mr Trump, who is at his Florida resort for the Christmas holiday, gave no details about what prompted his tweet.  

Representatives for his transition team did not immediately respond to a request for comment.

Mr Trump, who won the election on 8 November and takes office on 20 January, campaigned on a platform of building up the US military, but also pledged to cut taxes and control federal spending.

The President-elect met yesterday with a dozen Pentagon officials involved with defence acquisition programmes, as well as the chief executives of Lockheed Martin Corp and Boeing Co, the country's two largest defence contractors.

Mr Trump said he talked with the CEOs about lowering costs for two high-profile programmes: Lockheed Martin's F-35 fighter jets and Boeing's replacement 744-8s for the presidential Air Force One plane.

Defence stocks were little changed after Mr Trump's tweet, but shares of small uranium miners including Uranium Resources Inc and Uranium Energy Corp rose sharply.