Riyadh: The Obama administration is seeking to advance talks among Saudi Arabia and its neighbours on a missile defence system against Iran, while slowing any plans among Gulf states to intervene militarily in Syria.

US Secretary of State Hillary Rodham Clinton met for almost two hours with Saudi King Abdullah Bin Abdul Aziz on Friday, conferring on regional military strategy and how to increase oil sanctions against Iran while ensuring ample global petroleum supplies. Governments are under pressure to reduce purchases of Iranian crude, and the US hopes Saudi supplies can ease the transition.

The talks are occurring amid increased international concern over Iran's uranium enrichment activity and speculation that military action by the US or Israel may occur. The US, Israel and some Arab countries accuse Iran of trying to build nuclear weapons, but the Islamic republic insists its programme is solely for peaceful energy and research purposes.

In Washington, US President Barack Obama said on Friday he was plowing ahead with potential sanctions against countries that keep buying oil from Iran, including US allies, in the deepening campaign to starve Iran of money for its nuclear programme. The world oil market is tight but deep enough to keep the squeeze on Iran, Obama said.

US officials didn't provide all the details of Clinton's meeting with King Abdullah, which included an hour when the two spoke privately without any aides present. They expressed a shared commitment to a stable international oil market, senior State Department officials said, outlining the discussions on condition of anonymity.

America's top diplomat and the Saudi monarch also discussed coordination among the Gulf states on how to unite their defensive capacities into a cohesive regional strategy.

The talks will continue Saturday at a security conference bringing together the US and the Gulf states. They will also discuss UN mediation efforts to end a year of repression by Syrian President Bashar Al Assad's regime.