The European Union has said it believes a deal on trade tariffs with the US is "within reach", ahead of a 1 August deadline when President Donald Trump has threatened to impose a sweeping 30% levy on EU imports.

Hopes were raised after EU diplomats suggested the US had proposed a broad 15% tariff on most European imports.

A European Commission spokesman refused to speculate on the latest talks on Thursday, but said EU negotiators were working "might and main" to deliver a deal for Europe's consumers and companies.

White House spokesman Kush Desai said earlier that any talk about deals should be seen as "speculation" unless it was confirmed by the president.

Trump said on Wednesday that his condition for withdrawing the threatened 30% levy on EU imports was "if they agree to open up the [European] Union to American businesses".