.
The 70-year-old tycoon, who will take office in the White House next month, made the comments in an off-air conversation on MSNBC's “Morning Joe” today.
It came after Trump made calls to “greatly strengthen and expand” America’s nuclear arsenal in a tweet last night.
He wrote: "The United States must greatly strengthen and expand its nuclear capability until such time as the world comes to its senses regarding nukes.”
His message came hours after Russian President Vladimir Putin said their country needed to bolster its military potential – threatening a new Cold War era.
Putin today responded to Trump's statement saying that Russia is "stronger than aggressor".
At his annual end-of-year press conference, the confident Kremlin strongman insisted there was "nothing unusual" about the tweet.
He said: "We will never look to be dragged into an armed race and to spend resources that we can't afford."
After insisting he understood the US was the stronger military power, the Russian leader added: "We just say that we are stronger than any aggressor".
Trump's statement also came less than 24 hours after he met with three US Air Force generals for a discussion expected to include talk of modernising the country’s nuclear triad.
The triad is America’s ability to deploy nuclear weapons from land, sea and air.
He also met with chief executives of Lockheed Martin Corp and Boeing Co, the country's two largest defence contractors.
Trump repeatedly argued during the presidential election campaign that the US needs to modernise its ageing nuclear infrastructure – to keep up with rivals.
He said: “Our nuclear program has fallen way behind and they've gone wild with their nuclear program.
Not good. Our government shouldn't have allowed that to happen.
“We are old. We're tired. We are exhausted in terms of nuclear. A very bad thing.”
In March, he said: “Somebody hits us within IS, you wouldn’t fight back with a nuke?”
He added if the US wasn’t prepared to use the weapons then: “Why are we making them? Why do we make them?
“Nuclear should be off the table - but would there be a time when it could be used? Possibly.”
During the campaign he also said that Japan and South Korea should consider arming themselves with nuclear weapons in order to defend against North Korea.
The US has 7,100 nuclear weapons and Russia has 7,300, according to the US nonpartisan Arms Control Association.
America's nuclear submarines are all more than 30-years-old and its most dominant bomber jets are the 60-year-old B-52s.
The Pentagon has also called for upgrading the US arsenal of intercontinental ballistic missiles.
It estimated that £14billion over the next 15 years to modernise the nuclear triad.
Putin was quoted as saying on Wednesday: “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.”
Trump, who is at his Florida resort for Christmas, gave no details about what prompted his tweet yesterday.
Representatives for his transition team did not immediately respond to a request for comment.
We pay for your stories! Do you have a story for The Sun Online news team? Email us at tips@the-sun.co.uk or call 0207 782 4368.