A selloff in equities spread to Asia after President Donald Trump’s pledge to impose tariffs on trading partners raised the specter of a trade war hitting global economic growth. Treasury yields tumbled to the lowest in more than four months.

Asian shares sank to the lowest level in a month after the S&P 500 saw its worst selloff this year as the US president said Mexico and Canada couldn’t negotiate a reprieve from tariffs set to take effect Tuesday. Trump also signed an order doubling a levy on China to 20%. Oil dropped to the weakest level in three months and a gauge of the largest 100 digital tokens tumbled.