Hillary Clinton said the Gulf nations have been very responsive to enforcing international sanctions against Iran [EPA]

Hillary Clinton has called on world governments to keep pressure on Iran over its disputed nuclear programme, saying it "remains a serious concern".

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.

Clinton said this in Abu Dhabi on Sunday as part of a five-day trip to the United Arab Emirates, Oman and Qatar, which sit just across the Gulf from Iran, in a bid to rally support for tighter sanctions against the Islamic republic.

The US is seeking greater co-operation from its Gulf Arab allies in enforcing the international sanctions.

Clinton urged countries in the region doing business with Iran "to do everything within reason" to help ensure the sanctions are enforced.

"I don't know that it gives much comfort to someone who is in the Gulf or in a country that Iran has vowed to destroy that it's a one-year or three-year timeframe.

"So, I think we should keep the focus where it belongs,'' she said, referring to the sanctions and efforts by world powers to persuade Iran to halt uranium enrichment.

Israel, which has the Middle East's sole of undeclared nuclear arsenal, regards Iran as its principal threat.

Clinton's comments were the first from a senior US official in response to reports in Israel on Friday that Israel's newly-retired spy chief thinks Iran will not be able to build a nuclear bomb before 2015, further pushing back Israeli intelligence estimates of when Tehran might become a nuclear power.

Serious concerns

"We don't want anyone to be misled by anyone's intelligence analysis," Clinton said.

"This remains a serious concern. We expect all our partners ... to stay as focused as they can and do everything within reason that will help to implement these sanctions."

Many Arab nations share US fears that Iran is using a civilian atomic energy programme to hide weapons development.

The concerns were amplified in  leaked US diplomatic cables released by the WikiLeaks whistleblowing website late last year that revealed deep mistrust of Iran by Sunni Arab leaders who must deal with an increasing emboldened Shia neighbour.

Clinton's tour of the three Gulf states was to ask the leaders for insight into events in Iranand discuss how to make progress in a new round of multilateral talks with Iran scheduled later this month in Turkey.

The United States, Russia, China, Britain and France, the five permanent members of the UN Security Council, along with Germany will again try to compel Iran to come clean about its nuclear intentions, in return for incentives.

Iran is already under four sets of UN sanctions because of its refusal to halt uranium enrichment, which can be used to produce nuclear fuel or materials for bombs.

Tehran insists its uranium enrichment and other programmes are meant only for peaceful purposes to generate fuel for a future network of nuclear reactors.

Clinton's trip to the Gulf will be her second in as many months. She will head to Oman on Monday and Qatar on Tuesday, where she will address a regional conference of delegates from the business and civil society communities.

Source: Agencies