BERLIN, March 26 (Xinhua) -- The prospect of a global trade war provoked by U.S. President Donald Trump's protectionist "America First" doctrine is dampening the mood of German exporters, a study published Monday by the Ifo Institute for Economic Research (Ifo) found.

Business sentiment in March among 2,700 firms polled by the Munich-based institute fell to the lowest level since January 2017.

"The protectionist debate is leaving its mark on German exporters," a statement by Ifo president Clemens Fuest read.

A raft of new U.S. tariffs on steel and aluminium imports were enacted on Friday, although the European Union (EU), Canada, Mexico, Argentina, Brazil and Australia have obtained exemptions. The measures have widely been interpreted as targeting China, prompting Beijing to threaten Washington with retaliation unless it returns to the path of constructive multilateralism.

Even if Germany itself may not be affected by the tariffs, Ifo argued that the development is a source of concern to business leaders in the export-oriented country. Earlier, German Chancellor Angela Merkel had urged the United States to show restraint, emphasising "no one can win this kind of race" and reiterating Berlin's "clear dedication to multilateralism."

The German chancellor's intervention was only one of many strong reactions by heads of state, international governance organizations, and think tanks against Washington's turn toward protectionist policies.

Germany once again recorded the world's single largest current account surplus (the sum of a country's balance of trade and net income from international investments) in 2017 and would therefore be particularly exposed to the negative consequences of an international trade war.