Dhaka, July 8 -- US President Donald Trump on Monday began telling trade partners - from powerhouse suppliers like Japan and South Korea to minor players - that sharply higher US tariffs will start August 1, marking a new phase in the trade war he launched earlier this year.

The imposition of the 25 per cent levy on US importers of all goods from key allies Japan and South Korea rattled Wall Street, with the S&P 500 Index knocked back sharply, though markets in Asia were taking the latest news in stride.

The 14 countries sent letters so far, which included smaller US exporters like Serbia, Thailand and Tunisia, hinted at opportunities for additional negotiations while at the same time warning that any reprisal steps would be met with a ...