US military modernising nuclear weapons arsenal

The US military is modernising its nuclear weapons arsenal, in response to concerns that Russia is expanding its capability.

The new Pentagon strategy ends the Obama-era push to reduce America’s stockpile.

Defense Secretary James Mattis says the US needs to ‘see the world as it is’, not as it wishes it to be.

The US also wants to build a new kind of weapon which critics say could make nuclear war more likely.

Al Jazeera’s Defense correspondent Patty Culhane reports from Washington, DC.