US President Donald Trump voiced frustration on Friday with Iran’s stance in nuclear negotiations but said he had not yet decided whether to carry out a threatened attack, as US staff were authorised to leave Israel due to heightened risks. Trump has ordered the biggest military build-up in decades in the Middle East, with the world’s largest aircraft carrier, the USS Gerald R. Ford, approaching the coast of Israel, as he demands Iran agree to sweeping concessions on concerns starting with its...