The Standard & Poor's 500 index eased 0.3% this week as the Trump administration unveiled plans for new tariffs on pharmaceuticals, trucks and furniture.

The S&P 500 ended Friday's session at 6,643.70, marking the gauge's first weekly decline since the week ended Aug. 29.

With two trading sessions remaining in September, the S&P is up 2.8% for the month and 13% this year.

President Donald Trump said the US will impose tariffs of 25% on heavy trucks and 50% on kitchen cabinets and bathroom vanities, effective Wednesday. Additionally, the US will charge 100% levies on branded or patented pharmaceutical products.

The new tariffs added to investors' inflation concerns. Earlier this week, Fed Chair Jerome Powell said policymakers face a "challenging situation," with near-term risks to costs tilted to the upside and those to employment leaning downside.

The annual headline personal consumption expenditures price index advanced 2.7% last month, compared with 2.6% growth in July, but met market expectations. The Fed's preferred core measure, which excludes food and energy, held steady at 2.9% in August and also met consensus expectations.

By sector, communication services had the largest drop this week, falling 2.7%, followed by a 2% decline in materials and a 1.2% slip in consumer discretionary. Consumer staples, health care and financials also moved lower.

Facebook parent Meta Platforms (META) fell 4.5% in the week, and Google parent Alphabet (GOOGL, GOOG) dropped 3.2%, weighing down the communication services sector. Meta and Alphabet were among companies that lost their bid to bar expert testimony about the impact of social media on young users during looming trials against the companies.

Freeport-McMoRan (FCX) shares tumbled 20%, the biggest drop in the materials sector, as search efforts were underway for PT Freeport Indonesia contractors who were trapped in its Grasberg Block Cave underground mine in Indonesia following a Sept. 8 mud flow incident. The company said it was able to locate two personnel, who sustained fatal injuries, while a search continues for five remaining workers.

Freeport-McMoRan also said its Q3 consolidated sales are expected to be 4% lower for copper and down 6% for gold versus July estimates.

Meanwhile, the energy sector rose 4.7% this week, followed by a 2.8% gain in utilities and a 0.9% advance in real estate. Technology and industrials edged higher.

Halliburton (HAL) shares rose 12% this week, and Devon Energy (DVN) gained 9%, leading the energy sector, as crude oil futures gained.

Economic data expected next week include September payrolls and unemployment on Friday.