Brazilian coffee exporters warned on Wednesday of a market slowdown driven by uncertainty surrounding the latest round of U.S. tariffs, calling the new policy a blow to global trade sentiment.

"We're seeing a cooling of the market due to the uncertainty triggered by the tariff hike announced by U.S. President Donald Trump," said Marcio Ferreira, president of the Brazilian Coffee Exporters Council. "This has shaken global markets including coffee."

At the release of a monthly trade report, Ferreira noted that the United States remains the top buyer of Brazilian coffee.

Brazil exported 3.287 million 60-kg bags of coffee in March, down 24.9 percent from a year ago. However, export revenues jumped 41.8 percent year on year, despite the drop in volume-suggesting strong global prices.

In the first quarter, Brazil's coffee exports fell 11.3 percent compared to the same period last year.

The United States has recently imposed a 10 percent tariff on Brazilian imports, following earlier duties of 25 percent on Brazilian steel and aluminum.

Brazil is the world's leading producer and exporter of coffee.