US Secretary of State Hillary Clinton has asked Arab states in the Gulf to stay focused on sanctions against Iran over its nuclear programme, saying it remains a serious concern.Clinton said this in Abu Dhabi today as part of a five-day trip to the United Arab Emirates, Oman and Qatar. Clinton urged countries in the region doing business with Iran to do everything within reason to help ensure the sanctions are enforced. The US secretary of state said efforts to maintain sanctions must continue despite recent estimates that Iran may not be as advanced in developing atomic weapons as previously thought. Ms. Clinton will go to Oman tomorrow and Qatar the next day, where she will address a regional conference of delegates from the business and civil society communitiesThe five permanent members of the UN Security Council and Germany will meet Iran on nuclear issue. Iran is already under four sets of UN sanctions because of its refusal to halt uranium enrichment. Tehran insists its uranium enrichment and other programmes are meant only for peaceful purposes to generate fuel for a future network of nuclear reactors.