Trump criticised Iran’s approach to diplomacy and suggested it had not demonstrated a willingness to commit to an agreement preventing the development of nuclear weapons.

“They don’t know how to sign a non-nuclear deal,” Trump said, adding that Iranian leaders needed to act with greater urgency and judgment to move talks forward.

His comments highlight mounting frustration in Washington over the lack of progress in efforts to curb Iran’s nuclear programme, with both sides divided over the scope and timing of any potential agreement.