The state of Oregon, together with 23 other states, filed a lawsuit on Thursday seeking to block a new round of tariffs announced by US President Donald Trump.

The lawsuit, filed in the US Court of International Trade, argues that the tariff policy violates federal law, undermines constitutional separation of powers, and breaches the Administrative Procedure Act.

Oregon Attorney General Dan Rayfield said in a statement that the lawsuit challenges the administration's latest attempt to increase tariffs worldwide without approval from the US Congress.

"The focus right now should be on paying people back, not doubling down on illegal tariffs," Rayfield said, adding that many US citizens are already struggling with rising prices of groceries, clothing and other necessities.

According to the statement, Trump has imposed tariffs for more than a year without proper legal authority. The president initially argued that the International Emergency Economic Powers Act (IEEPA) allowed him to levy tariffs on products from any country at any level and for any duration.

However, the US Supreme Court ruled on February 20 that tariffs imposed under the IEEPA were unlawful. Following the ruling, Trump invoked another law, Section 122 of the Trade Act of 1974, and announced tariffs of 15% on most products worldwide, citing trade deficits as justification, the statement said.

"That law authorizes tariffs in limited circumstances, including when there are 'large and serious balance-of-payments deficits'" in the United States, it said. A trade deficit does not constitute such a condition, meaning that once again Trump "is acting unlawfully."

A recent analysis by researchers at the Federal Reserve Bank of New York found that nearly 90% of tariff costs in 2025 were paid by US consumers and businesses, according to the statement.

Experts also estimate that the tariffs could increase the cost of living for an average Oregon family by more than $1,200 per year, the statement said.