He took aim at NBC, which made him a star on The Apprentice, after it reported he wanted to boost America’s nuclear arsenal almost tenfold.
Mr Trump labelled the report “fake news” and pure fiction”.
NBC also angered the White House last week when it reported the secretary of state had called Mr Trump “a moron”.
The US president tweeted on Wednesday: “Fake @NBCNews made up a story that I wanted a ‘tenfold’ increase in our US nuclear arsenal. Pure fiction, made up to demean. NBC = CNN!”
According to NBC News, Mr Trump told a top-level meeting at the Pentagon in July he wanted to dramatically increase the American stockpile of atomic missiles.
He reportedly made the request after seeing a downward-sloping curve on a briefing slide charting the steady reduction in US nuclear weapons since the 1960s.
Attributing its report to three officials in the room, NBC said Mr Trump’s request surprised those present, including the Joint Chiefs of Staff and Rex Tillerson.
The network also reported that Mr Trump also called for additional US troops and military equipment.
More at Source: Trump threatens broadcaster NBC after nuclear report – BBC News