A federal judge has struck down the $100,000 fee that U.S. President Donald Trump imposed on new H-1B visas for highly skilled foreign workers, ruling that it constituted an unlawful tax that Congress never authorised.

According to Antigua News Room, U.S. District Judge Leo Sorokin in Boston issued the ruling in a lawsuit brought by 20 Democratic state attorneys general. The lawsuit challenged a fee Trump announced in September that dramatically raised the cost of obtaining H-1B visas.

The Trump administration had argued the fee was a lawful monetary penalty that the president was authorised to impose under federal immigration law, which grants him the power to restrict the entry of certain foreign nationals when he deems it "detrimental to the interests of the United States."

Judge Sorokin rejected that argument, concluding that the payment was not a penalty but a tax — one the president lacked congressional authorisation to impose. He further ruled that the U.S. State Department and U.S. Citizenship and Immigration Services could not implement it.

"Here, the substance and application of the $100,000 payment reveal that it is a tax, regardless of what the payment is called," wrote Sorokin, who was appointed by Democratic President Barack Obama.

The judge also cited the U.S. Supreme Court's February ruling striking down Trump's sweeping tariffs pursued under a law intended for national emergencies. Applying the logic of that decision, Sorokin found that Trump similarly lacked authority under immigration law to levy the fee.

The White House pushed back swiftly. Spokeswoman Taylor Rogers said the administration is confident Sorokin's order will be reversed on appeal. "President Trump has clear legal authority to restrict entry of any class of aliens he determines is not in America's best interests, and that is exactly what he did," she said.

The H-1B programme offers 65,000 visas annually, with an additional 20,000 visas available for workers with advanced degrees, approved for three to six years. Technology companies in particular rely heavily on workers who obtain H-1B visas.

Prior to Trump's proclamation, employers seeking a visa for a foreign worker typically paid between $2,000 and $5,000 in fees depending on various factors. The $100,000 fee does not apply to foreign citizens already in the United States on student visas, who generally make up a large share of new H-1B recipients.

The dramatic fee increase has discouraged H-1B visa applications, according to court filings. As of February 15, U.S. Citizenship and Immigration Services had received just 85 payments of the $100,000 fee, the administration stated in a March filing.

The Trump administration has also ordered enhanced vetting of H-1B applicants and proposed a new visa selection process that would favour higher-skilled and better-paid workers.

The $100,000 fee has prompted at least three separate lawsuits challenging its implementation, including a case filed by the U.S. Chamber of Commerce. That organisation is currently appealing a December decision by a Washington, D.C. judge who rejected its claims that Trump lacked authority to set the fee.