American tariffs on dozens of countries will come into effect next Wednesday as scheduled, although several deals could still be worked out before then, President Donald Trump confirmed Friday.

Trump announced the Vietnam deal on Wednesday, saying that the US would place a 20 per cent tariff on Vietnamese exports to the US and a 40 per cent rate on goods deemed transshipped through the nation — a reference to the practice whereby components from China and possibly other nations are routed through third countries on their way to the US.

Trump told reporters he would begin sending countries letters setting tariff rates rather than negotiate 170 trade deals worldwide.