Berkshire Hathaway's CEO challenges new trade tariffs affecting Mexico, Canada, and China. Warren Buffett's rare public statement signals growing market concerns.

The tariff on imported Japanese cars has been cut to 15%, down from 25%, in a deal announced by President Donald Trump.

Goods coming to US from Japan will be tariffed at 15 percent, but Canadian and Mexican goods still face 35 and 30 percent ...