The lowering of U.S. tariffs on Switzerland to 15% from 39% will be effective retroactively from November 14, the Swiss government said on Wednesday, delivering relief to businesses that had been saddled with the highest U.S. duties in Europe.

On November 14, the United States and Switzerland sealed a preliminary agreement under which Washington would cut the tariffs on Swiss goods, while Swiss companies pledged to invest $200 billion in the U.S. by the end of 2028.

The trade-weighted U.S. tariff burden on Swiss goods will now be some 10 percentage points lower than under the 39% rate at an estimated 7% to 9%, the Swiss government said.

Last month, the two sides agreed any additional U.S. tariffs on pharmaceutical products, which account for much of Swiss exports, would not exceed 15% under so-called section 232 investigations that probe possible threats to national security.

Still, Swiss Economy Minister Guy Parmelin, who led the tariff negotiations with the United States, noted the Trump administration had previously floated the possibility of higher tariffs for prescription drugs, making the future uncertain.

"You never know what could happen," Parmelin told a press conference on the tariffs, shortly after parliament voted to confirm he would serve as president next year under Switzerland's rotating one-year system.

U.S. President Donald Trump imposed the 39% duties on Switzerland in August, saying they were justified by the U.S. trade deficit with the Alpine country.

The tariffs, the highest the Trump administration put on any European country, stunned the Swiss business community.

Swiss companies have welcomed the tariff reduction, which puts them on a level playing field with EU competitors.

The two countries must still finalize their agreement in negotiations they hope to conclude by the first quarter of 2026. Parmelin said the United States understood the process of formalizing the agreement in Switzerland could take time.

Many businesses have held back on sending goods while waiting for lower tariffs to come into force.

Swiss army knife manufacturer Victorinox said it was relieved about tariff reductions for its biggest export market.

"This step creates a significantly more manageable framework for our exports to the United States," said CEO Carl Elsener.

The lower tariffs would boost Swiss economic growth by 0.3 to 0.5 percentage points next year, said Hans Gersbach, an economist at the KOF Institute at ETH in Zurich.

-John Revill and Dave Graham