U.S. President Donald Trump's 50% tax on steel and aluminum began to take effect, and U.S. tariffs have once again attracted attention in Europe.

The order was announced last week and signed by Trump, which raised tariffs on all metal imports from 25% to 50%, and the president said the move would protect the U.S. steel industry in amid cheaper foreign steel imports and weaker global demand.

Canada and Mexico are the largest steel exporters in the United States, including Brazil and South Korea.

European steel exporters, including those in Germany, Italy, Sweden and the Netherlands, will be hit hard by the new 50% tax. Britain received temporary probation, with 25% tariffs remaining, and details of the recent trade agreement signed by Britain with the United States have been resolved.

Trump said in a signing of the steel tariff order on Tuesday that Britain must “different treatment” for its European counterparts due to the signing of the “economic boom agreement” on May 8.

The 25% tariff is expected to be revoked as part of the trade deal, although Trump warned that it could even raise the UK tax to 50% if the White House “if the White House” determines that Britain does not comply with relevant aspects of the EPD.

According to UK Steel, the United States accounts for 7% of the UK's total steel exports, and the industry is worth £370 million ($500 million).

Trade agency director-general Gareth Stace said on Tuesday that the UK's exemption of 50% of its duties was a "happy pause" but urged London and Washington to turn their trade deal into reality to eliminate tariffs altogether.

"The ongoing 25% tariff will benefit the goods we are worried about already causing on the water," he said in a statement.

"But the uncertainty remains in time and final tariff rates, and now U.S. customers will be doubtful about whether they should risk the orders they should be taking the order," he added.

Meanwhile, the EU is angry at about 50% of steel tariffs, saying such a move “destroys” ongoing trade deal negotiations with the United States

An EU spokesman said the group was "prepared to impose countermeasures" although it provided no further details about the forms that could be taken.

"If no mutually acceptable solutions are achieved, existing and other EU measures will automatically take effect on or before July 14 (if required)," a spokesperson said.

Analysts say Trump's tariffs will force U.S. steel prices to rise, leading to higher prices in industries such as automakers, and consumers who buy canned food and beverages.

But while the impact of inflation on domestic prices in the U.S. will be widely expected to be severe, Europe's impact will be more mixed, with some buyers and manufacturers able to benefit from lower prices as more steel is redirected to the region, analysts told CNBC this week.