Business activity in eurozone declined this month as the threat of higher duties on exports to the U.S. added to political uncertainties at home, according to surveys released Friday.

The Composite Purchasing Managers' Index published Friday by Hamburg Commercial Bank and S&P Global declined to 48.1, its lowest level since the beginning of the year. A reading below 50 points to economic contraction. The index had been expected to drop less sharply, according to economists surveyed by The Wall Street Journal.

A particular cause of concern is the likelihood of steeper import tariffs in the U.S., a key plank of Donald Trump's successful presidential election campaign. Eurozone firms scaled back their workforces over the month, HCOB said.

Trade uncertainty adds to political turmoil in the eurozone's two largest members. The French government of Michel Barnier remains shaky, while German premier Olaf Scholz was forced this month to call snap elections after his governing coalition collapsed.

"Political uncertainty, which has increased since Donald Trump's election as U.S. president and the announcement of snap elections in Germany on Feb. 23, isn't helping," said Cyrus de la Rubia, an economist at HCOB.

Write to Joshua Kirby at [email protected]; @joshualeokirby