President Donald Trump posted letters to the leaders of Mexico and the European Union, saying they had not done enough to head off the new tariffs.

The European Commission responded to Trump's announcement in a written statement, saying it remains ready to reach an agreement, while also taking "necessary steps to safeguard EU interests, including the adoption of proportionate countermeasures.

The EU remains hopeful it will strike a deal to avoid steep levies Trump has threatened on its exports to the US.

NEW YORK (Reuters) -Investors awaited tariff news between the U.S. and European Union on Friday that could add a potentially volatile development to the end of a week in which President Donald Trump reignited his global trade war.