China on Tuesday announced retaliatory tariffs and export controls, as President Donald Trump's tariffs on goods from China, Canada and Mexico went into effect

Mexico is expected to announce its response later.The three major stock market indexes in the US sank following the news, while the FTSE 100 index of the UK's biggest publicly-listed companies opened sharply lower on Tuesday and stock markets in Asia were also down.

Starting just past midnight, imports from Canada and Mexico are now to be taxed at 25%, with Canadian energy products subject to 10% import duties.