US President Donald Trump has warned that a potential Supreme Court ruling limiting his authority to impose tariffs would threaten national security.

The Supreme Court is currently reviewing challenges to Trump’s wide-ranging use of tariffs, with businesses and Democratic-led states arguing that such powers belong to Congress, not the presidency.

Defending tariffs as crucial to US economic strength and security, Trump said on social media that a negative decision would leave the country “financially defenseless”. His comments come amid rising living costs and political scrutiny, as inflation hit 2.8 percent year-on-year in September.