U.S. President Donald Trump speaks during a press briefing at the White House, following the Supreme Court's ruling that Trump had exceeded his authority when he imposed tariffs, in Washington, D.C., Feb. 20. Reuters-Yonhap

WASHINGTON — U.S. President Donald Trump imposed Friday an additional 10 percent tariff on imports into the United States after the Supreme Court struck down many of his sweeping and often arbitrary duties, delivering a stinging rebuke on his signature economic policy.

Trump signed the tariff order in the Oval Office — saying on social media it was "effective almost immediately" — after spending the past year imposing various rates to cajole and punish countries, both friend and foe.

The new duty is slated to take effect February 24 for 150 days, with exemptions remaining for sectors that are under separate probes, including pharma, and goods entering the U.S. under the U.S.-Mexico-Canada agreement, according to a White House factsheet.

U.S. trading partners that reached tariff deals with Trump's administration will now also face a 10 percent duty, despite higher levels they may have agreed on previously, the White House said.

But a White House official told AFP that the Trump administration would seek ways to "implement more appropriate or pre-negotiated tariff rates" down the line.

Earlier Friday, the conservative-majority high court ruled six to three that a 1977 law Trump has relied on to slap sudden rates on individual countries, upending global trade, "does not authorize the President to impose tariffs."

Trump, who had nominated two of the justices who repudiated him, responded furiously, alleging without evidence that the court was influenced by foreign interests.

"I'm ashamed of certain members of the court, absolutely ashamed, for not having the courage to do what's right for our country," Trump told reporters.

"In order to protect our country, a president can actually charge more tariffs than I was charging in the past," Trump said, insisting that the ruling left him "more powerful."

Source: Korea Times News