The European Union (EU) and Mexico have expressed disappointment at US President Donald Trump's threat to impose 30% tariffs on their imports from 1 August.

Mexico criticised what it called Trump's "unfair deal" and insisted its sovereignty is non-negotiable, while the EU's chief, Ursula von der Leyen threatened to take "proportionate countermeasures", if needed. Both said they want to keep negotiating with the US.

Trump has warned he would impose even higher import taxes if either of the US trading partners decided to retaliate.

This week Trump also announced new tariffs on goods from Japan, South Korea, Canada and Brazil from next month.

In the letter sent on Friday to European Commission President Ursula von der Leyen, Trump wrote: "We have had years to discuss our trading relationship with the European Union, and have concluded that we must move away from these long-term-large, and persistent, trade deficits, engendered by your tariff, and non-tariff, policies and trade barriers."

"Our relationship has been, unfortunately, far from reciprocal," the letter added.

In his letters to the EU and Mexico, Trump warned that if either trade partner retaliated with import duties of their own against the US, he would hit back by raising tariffs by a similar percentage over and above the 30%.

The EU has been a frequent target of Trump's criticism. On 2 April, he proposed a 20% tariff for goods from the bloc, as well as dozens of other trade partners. He then threatened to raise the EU import taxes to 50% as trade talks stalled.

Washington and Brussels had hoped to reach an agreement before a deadline of 9 July, but there have been no announcements on progress.

In 2024, the US trade deficit with the bloc was $235.6bn (€202bn; £174bn), according to the office of the US trade representative.

Von der Leyen said the EU remained ready "to continue working towards an agreement by Aug 1".

"We will take all necessary steps to safeguard EU interests, including the adoption of proportionate countermeasures if required," von der Leyen said.

"Few economies in the world match the European Union's level of openness and adherence to fair trading practices," her statement added.

The 27-member EU said earlier this week it hoped to agree a deal with Washington before 1 August.