U.S. President Donald Trump on Saturday announced that he will raise a newly imposed global tariff from 10 percent to 15 percent, escalating trade tensions just one day after the Supreme Court struck down his previous tariff regime.

In a social media post, Trump said he would increase the 10 percent "Worldwide Tariff" to a "fully allowed, and legally tested" 15 percent level, effective immediately. He argued that many countries had been "ripping off" the United States for decades and pledged to introduce additional "legally permissible" tariffs in the coming months to advance his economic agenda.

The move came swiftly after the Supreme Court ruled 6–3 on Friday that Trump's earlier tariffs, imposed under the International Emergency Economic Powers Act (IEEPA), were illegal. Within hours of the ruling, Trump signed an executive order introducing a 10 percent across-the-board tariff – now raised again to 15 percent – signaling that his trade offensive is far from over. 

A growing refund fight

While the White House presses ahead with new measures, the legal and financial fallout from the court's decision is mounting.

Hundreds of companies, including retail giant Costco, have filed lawsuits seeking refunds for tariffs paid under the now-invalidated IEEPA (International Emergency Economic Powers Act) policy. Reuters reported that more than 1,000 cases have been brought before U.S. trade courts. Some Democratic lawmakers have also urged the administration to return the collected funds.

According to U.S. Customs and Border Protection data released last December, tariffs imposed under IEEPA generated approximately $130 billion in revenue. Estimates from the University of Pennsylvania suggest the total may now exceed $175 billion.

Yet how and whether that money will be refunded remains unclear. Legal experts say the U.S. Court of International Trade will ultimately determine the scope of compensation, and the process could drag on for years.

Complicating matters further, economists argue that the economic burden of the tariffs has largely been absorbed by U.S. businesses and consumers. Research from economists at the Federal Reserve Bank of New York found that nearly 90 percent of tariff-related costs were borne domestically.

However, ordinary consumers cannot easily prove how much of the tariff they effectively paid, leaving them unlikely to qualify for refunds. Many small businesses also absorbed part of the cost to protect market share, making precise calculations nearly impossible.

The Treasury has previously warned that large-scale refunds could significantly strain public finances. Government lawyers cautioned in court that such repayments might disrupt trade negotiations, trigger economic instability and cause diplomatic embarrassment. Trump himself said that the refund battle could result in a protracted legal struggle lasting "five years."

What's in Trump's tariff toolkit?

Despite the setback under IEEPA, Trump retains multiple legal avenues to pursue tariffs.

The latest tariff tool Trump used is Section 122 of the Trade Act of 1974, originally introduced during former U.S. President Richard Nixon's administration as a temporary tool to address balance-of-payments concerns. Unlike IEEPA, Section 122 applies on a non-discriminatory basis to all countries and does not require lengthy negotiations. However, it is limited to 150 days unless Congress grants approval for an extension.

The temporary window could allow the administration time to seek broader legislative backing or pivot to other legal mechanisms.

A frequently used legal option is Section 232 of the Trade Expansion Act of 1962, which permits tariffs on national security grounds. Trump previously relied on this provision to impose duties on steel, aluminum and automobiles.

In addition, Sections 201 and 301 of the Trade Act of 1974 allow the government to impose tariffs following investigations into "unfair" trade practices, such as intellectual property violations, forced technology transfers or discriminatory measures, to protect domestic industries.

Trump has even mentioned invoking Section 338 of the Smoot-Hawley Tariff Act of 1930 – a rarely used and more aggressive measure that permits the U.S. president to impose tariffs of up to 50 percent on countries deemed to engage in discriminatory trade practices, without requiring a formal investigation.

Analysts at HSBC suggest the administration could use Section 122 as a short-term bridge while completing Section 301 investigations, eventually transitioning to a more targeted tariff mechanism. Together, these tools underscore that the Supreme Court ruling may have constrained one pathway, but it has not ended the administration's broader trade strategy.

International responses

The tariff escalation has prompted swift reactions from major U.S. trading partners.

German Chancellor Friedrich Merz said he will travel to Washington to discuss the issue directly with Trump, emphasizing that tariffs ultimately harm all parties and weigh most heavily on consumers. Although the court ruling may ease some uncertainty, U.S. tariffs on sectors such as automobiles, steel and aluminum remain in place. Berlin is coordinating closely with other European Union members to develop a unified response.

France's minister delegate for foreign trade Nicolas Ferracci said Paris is consulting with EU partners and the European Commission. He noted that the bloc has retaliatory tools available, including export controls, service-sector tariffs, restrictions on U.S. firms' access to EU procurement contracts, and a suspended countermeasure package targeting over 90 billion euros worth of American goods.

Canada welcomed the Supreme Court's decision but highlighted ongoing challenges, as U.S. tariffs on steel, aluminum and automobiles remain intact. Uncertainty also surrounds the upcoming review of the U.S.-Mexico-Canada Agreement (USMCA). Although most bilateral trade has remained duty-free under USMCA exemptions, Canadian officials are preparing for high-stakes talks with U.S. Trade Representative Jamieson Greer ahead of the July 1 review. Washington has signaled it may favor separate bilateral deals over renewing the trilateral pact.

The Republic of Korea's presidential office convened an emergency meeting to assess the impact of the new U.S. tariffs. Officials said Seoul will closely monitor developments, maintain communication with business groups, and continue consultations with Washington to protect export conditions and preserve the achievements of the Korea-U.S. trade agreement.

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