Donald Trump has extended the deadline for a tariff deal with Mexico by another 90 days, fuelling speculation he could announce pauses for dozens of other countries that face punitive higher import duties from Friday.

As the countdown continues to his deadline for a trade deal – already extended by four weeks from the original 90 days – the US president said he had made the decision to offer more time to Mexico because of the complexities of the trading relationship.

He wrote on social media: “We will be talking to Mexico over the next 90 Days with the goal of signing a Trade Deal somewhere within the 90 Day period of time, or longer.”

A little more than two weeks ago Trump threatened the EU and Mexico with tariffs of 30% on most exports to the US, but last Sunday he concluded a deal with Brussels with a 15% baseline rate from 1 August.