Donald Trump’s new national defence strategy named “inter-state strategic competition” as its primary concern rather than jihadist attacks.
It marks a tipping point after almost two decades when the US has focussed on countering terrorism following the September 11 attacks.
China, Russia, North Korea and Iran were all mentioned as powers that were threatening the international order.
The strategy signals a return of a Cold War-style mentality in American foreign policy that will focus on countering rival great powers.
James Mattis, the US defence secretary, explained the rationale behind the 11-page national defence strategy in a speech on Friday.
“We will to continue to prosecute the campaign against terrorists that we’re engaged in today, but great-power competition - not terrorism - is now the primary focus of US national security,” he said.
Mr Mattis added: "To those who would threaten America's experiment in democracy: they must know if you challenge us, it will be your longest and worst day."
The document itself included a similar message: “Inter-state strategic competition, not terrorism, is now the primary concern in US national security.”
It called out threats posed by rival nations. “China is a strategic competitor using predatory economics to intimidate its neighbours while militarising features in the South China Sea,” it read.
“Russia has violated the borders of nearby nations and pursues veto power over the economic, diplomatic, and security decisions of its neighbours.
“As well, North Korea’s outlaw actions and reckless rhetoric continue despite United Nation’s censure and sanctions.
"Iran continues to sow violence and remains the most significant challenge to Middle East stability.”
John McCain, the Republican senator of Arizona, welcomed the strategy, saying: “It gets the big decisions right, prioritises the threats we face, and offers clear guidance for making tough choices.”
Mr Mattis also called on Democrats to agree new funding ahead of a midnight Friday deadline, warning that the military would suffer if they blocked budget proposals.
Appealing to Congress, he said: "No strategy can survive without predictable funding. As hard as the last 16 years have been, no enemy has harmed the US military more than defence spending caps and sequestration."
Mr Trump cancelled his trip to Florida on Friday in an attempt to help avoid a government shutdown as Republicans piled pressure on their political opponents.
The US president was due to fly to his Mar-a-Lago resort but stayed in Washington as scrambled negotiations played out behind the scenes.
A fierce blame game erupted in the American capital as political rivals pointed the finger at each other over who was at fault.
Mitch McConnell, the Republican leader of the Senate, accused Democrats of being unpatriotic by threatening to block a funding extension.
“The American people, the citizens who actually elected us, will be watching," he said.
"They will see which senators make the patriotic decision, stand up for the American people and vote to continue government funding."
Chuck Schumer, the most senior Democrat in the Senate, noted that Mr Trump once said that America could use “a good shutdown”.