Investors have warned that if US jobs data this week is worse than expected it could indicate the world’s largest economy is headed for a recession as a result of President Donald Trump’s tariff wars.

Trump on Saturday announced a plan to increase tariffs on foreign imports of steel from 25 per cent to 50 per cent to “further secure the steel industry in the United States”, unbowed by a court ruling this week that tried to put a handbrake on his global trade war.