'The threat is real' Obama confirms ISIS nuke plot 'to kill as many as possible'

THE threat of an ISIS nuclear terror attack is real, Barack Obama has warned, and countless lives could be at risk.

WARNING: Barack Obama said we cannot be complacent about the nuclear terror threat

The US president said Islamic State "madmen" were trying to get atom bombs and urged world leaders to up security at nuclear power plants.

And despite all efforts to reduce the risk, he said, humanity faced a persistent and evolving threat of nuclear terror and we "cannot be complacent".

"There is no doubt that if these madmen ever got their hands on a nuclear bomb or nuclear material, they would use it to kill as many innocent people as possible," he said.

TAKING ACTION: Barack Obama, John Kerry and David Cameron at the nuclear security summit

It comes as David Cameron warned thatBritish cities could be targeted by ISIS radioactive dirty bombs deployed with drones cheaply available on websites like Amazon.

While North Korea has vowed a terror attack on the West worse than 9/11 just hours before tubby tyrant Kim Jong-un conducted another high-tech rocket test.

Now with tensions at boiling point, world leaders have gathered in Washington DC for a nuclear security summit in a last-ditch attempt to stop WW3.

More than 50 nations have come together in the American capital, rallying against a threat which Obama said would "change our world".