Donald Trump has outlined a new Cold War-style approach to US foreign policy by framing Russia and China as competitors and stressing the importance of nuclear weapons.

The US president's first national security strategy, published on Monday, chastised previous administrations for their “complacency” since the Soviet Union's fall.

It said American nuclear weapons were “the foundation of our strategy to preserve peace and stability” and called for new “significant investment”.

The strategy document said Russia and China were trying to “challenge American power, influence and interests” and “erode American security and prosperity”.

And it warned against “engagement” with rivals, saying the belief they could be turned into “benign actors and trustworthy partners" had been proved wrong.

Climate change was also dropped as a national security concern - a change from Barack Obama's presidency.