Both US Secretary of State John Kerry and Iranian Foreign Minister Mohamed Zarif suggested Tuesday that extending the July 20 deadline for a final nuclear accord would not be ruled out by their governments. Major gaps remain in the six-power nuclear negotiations ongoing with Iran in Vienna. The US has said that Iran can’t be allowed to keep 15,000 centrifuges for enriching uranium or stand by its refusal to convert the Arak reactor to a light water plant unable to produce plutonium for a bomb. The Iranian negotiating team has its hands tied by the intransigent policies dictated by supreme leader Ayatollah Ali Khamenei.