- Video report by ITV News Washington Correspondent Robert Moore
Donald Trump has unveiled the new national security strategy which will put "America First".
The US President criticised previous leaders for failing to look out for the nation's citizens as he declared a new era of competition.
His strategy focuses on protecting the homeland, including building a wall on the US southern border and taking other steps on immigration. He also called for promoting American prosperity, demonstrating peace through strength and advancing American influence.
He said: "America is in the game, and America is going to win."
The US will cooperate with other countries "in a manner that always protects our national interests", he added.
But he insisted that the US "will stand up for ourselves and our country like we have never stood up before". He called for competing "with every instrument of our national power".
He denounced previous presidents for engaging in "nation building abroad while they failed to build up and replenish our nation at home", pointing to the economy's strong performance and predicting even better under his policies.
His security strategy envisions nations in constant competition, reverses Obama-era warnings on climate change and affirms that the US will unilaterally defend its sovereignty, even if that means risking existing agreements with other countries that have dominated foreign policy since the Cold War.
Mr Trump's doctrine holds that nation-states are in perpetual competition and that the US must fight on all fronts to protect and defend its sovereignty from friend and foe alike.
While the administration often says that "America First" does not mean "America Alone," the national security strategy makes clear that the US will stand up for itself even if that means acting unilaterally or alienating others on issues such as trade, climate change and immigration.
The last such strategy document, prepared by President Barack Obama in 2015, declared climate change an "urgent and growing threat to our national security." The Trump plan removes that determination following the administration's threat to pull out of the Paris climate accord.
The strategy sets a goal of being an "energy-dominant nation" and says that the US "recognises the importance of environmental stewardship".