Stock futures tumbled Sunday night to kick off a new trading month, as investors weighed new U.S. tariffs on goods from key trade partners and their potential impact on the economy and corporate profits.

Investors braced for a potential trade war after President Donald Trump imposed tariffs on goods from Canada, Mexico and China and pledged future tariffs on the European Union.

Global shares are mostly declining as worries grow about President Donald Trump imposing tariffs on key U.S. trading partners

By Shashwat Chauhan (Reuters) -Futures for Wall Street's main indexes tumbled on Monday as fears of a full-blown trade war and its impact on the global economy jolted markets around the world after President Donald Trump levied steep tariffs on Mexico,