Iranian Foreign Minister Abbas Araghchi has described the prospect of direct negotiations on its nuclear programme with the United States as “meaningless” amid mounting tensions between the two countries.

Araghchi’s remarks came in a statement on Sunday, after Trump said last month in a letter sent to Iran’s Supreme Leader Ayatollah Ali Khamenei that he hoped there would be a negotiation between their countries aimed at preventing Tehran from acquiring nuclear weapons.

Trump upped the ante last week, saying: “If they don’t make a deal, there will be bombing.”

Araghchi questioned Washington’s sincerity in calling for negotiations, saying on Sunday, “If you want negotiations, then what is the point of threatening?”

Tehran, which maintains that it is not seeking a nuclear weapon, has so far rejected Washington’s overtures, but has said it is open to indirect diplomacy – a stance repeated by Araghchi in Sunday’s statement.

Araghchi said Iran wanted to negotiate on an “equal footing” with the US, describing it as “a party that constantly threatens to resort to force in violation of the UN Charter and that expresses contradictory positions from its various officials”.