A dozen US states have joined together on a lawsuit aiming to block President Donald Trump's spate of tariffs that have upended global trade.

The suit, which is led by New York's governor and attorney general, argues that the president lacked the authority to impose the levies. It notes that such tariffs must be approved by the US Congress.

Twelve states joined the lawsuit, which was filed with the United States Court of International Trade.

The White House accused New York Attorney General Letitia James of "prioritising a witch hunt against President Trump over protecting the safety and well-being of their constituents".

White House spokesman Kush Desai added that the "administration remains committed to using its full legal authority to confront the distinct national emergencies our country is currently facing—both the scourge of illegal migration and fentanyl flows across our border and the exploding annual U.S. goods trade deficit."

The lawsuit states that tariffs must be approved by Congress and questions Trump invoking a 1970s law called the International Emergency Economic Powers Act (IEEPA) to enact the levies.

"By claiming the authority to impose immense and ever-changing tariffs on whatever goods entering the United States he chooses, for whatever reason he finds convenient to declare an emergency, the President has upended the constitutional order and brought chaos to the American economy," the lawsuit states.

Trump invoked the IEEPA as the basis for several of his tariffs against China, Mexico, Canada, and other countries.

A president can use the law "to deal with any unusual and extraordinary threat, which has its source in whole or substantial part outside the United States, to the national security, foreign policy, or economy of the United States," if he has first declared a national emergency.

The lawsuit argues that the law does not actually grant Trump the power he claims to derive from it. The act has never been used to issue tariffs by any president, congressional research shows.

Last week, the state of California filed its own lawsuit against the Trump administration over tariffs. That lawsuit also argues that Trump lacks the power under the IEEPA to impose these tariffs. Several other lawsuits have similarly challenged Trump's authority using that law for the levies.

Trump has implemented tariffs on global trading partners in a stated effort to correct what he believes is a trade deficit between the US and other nations.

On 2 April, in an event billed as "Liberation Day," Trump shook the global economy by announcing "reciprocal" tariffs on nations across the world. A few days later amid a market backlash, he announced a 90-day pause on the tariffs and lowered the rate to 10% for most countries.

That pause didn't extend to China, which Trump said had a "lack of respect" and was retaliating. Instead, the US issued a 145% tariff on goods imported from China, which has led to a trade standoff and rattled global markets.

On Wednesday, Trump said he hoped to come to a deal with China soon and noted the 145% tariff was "very high".

The White House has also imposed 25% tariffs on certain goods from it's neighbours, Mexico and Canada.