The United States and Saudi Arabia are trying to move beyond a public spat last year that saw strategic ties hit a nadir, as Western and Gulf security concerns align over the threat from Iranian drones, diplomats and regional experts say.

A senior US delegation visited Saudi Arabia this week for defence talks with the six-nation Gulf Cooperation Council, headquartered in Riyadh, that was postponed from October when a row erupted between Washington and Riyadh over oil policy.

"The working groups offer a way for the US to engage with Gulf partners on issues of mutual interest away from the political glare," said Kristian Coates Ulrichsen, a political scientist at Rice University's Baker Institute.

He said Russia's use of Iranian drones in the Ukraine war has "certainly concentrated minds in GCC capitals in a way that the initial Russian invasion of Ukraine probably didn't".

Saudi Arabia and the United Arab Emirates have resisted Western pressure to help isolate Russia, with which they have economic links, and limit ties with main trading partner China, whose president met with Gulf leaders in Riyadh in December.

The US-Saudi alliance was already strained under US President Joe Biden, who has taken a tough stance over Riyadh's human rights record but visited the kingdom last summer to press for more oil supplies.

When in October the OPEC+ oil alliance led by Saudi Arabia and which includes Russia decided to instead cut output targets, Biden vowed there would be consequences for Riyadh.

Two diplomats in the region said the US-Gulf talks showed both sides want to move forward and especially on an institutional level.

DRONES CHANGE THE GAME

Saudi analyst Abdulaziz Sager, speaking on state-run Ekhbariyah TV, said the entry of Iranian drones into Russia's war on Ukraine lent fresh impetus at a time when Gulf states were doubting the US' commitment to the region.

"This is when things really changed, when they (West) felt their security was threatened by Iran's support for Russia," said Sager, chairman of Riyadh-based Gulf Research Center.

Sunni Muslim power Saudi Arabia and its allies have long warned about regional rival Shi'ite Iran's missile and drone capabilities and proxy network, especially after attacks on Saudi oil facilities in 2019.

The US delegation, which included the US special envoy for Iran, focused on regional integrated air and missile defence and maritime security, Iran and counterterrorism.

Dana Stroul, deputy assistant secretary of defence for the Middle East, told reporters the discussions covered the "full set of threats from Iran" in the region and "increased Iranian-Russian military cooperation for use in Ukraine".

Stroul said discussions on integrated air and missile defence looked at increased intelligence sharing, early warning and "a more effective layered air defense", adding that progress depended on the pace at which individual countries were willing to move.

Security is paramount for Gulf energy producers, which rely heavily on the US security umbrella, as they vie for foreign capital to diversify their economies in a turbulent region.

Saudi Arabia and the United Arab Emirates resent US conditions on arms sales, however, including over the Yemen war that pits a Saudi-led coalition against the Iran-aligned Houthi group.

Questioning America's regional role, Gulf states have increasingly pursued their own national interests, including looking at diversifying their security and economic partners. The UAE and Bahrain, for example, have forged ties with Israel for a new anti-Iran axis.

"The integrated defence system is a good idea when all parties are under a single leadership, but the question remains... Can American promises be trusted?," Sager said.

A third diplomat and a Gulf source said US-UAE ties, also tested last year over what Abu Dhabi saw as a slow US response to Houthi missile and drone attacks on the country, were in a much better place with a focus on security matters.

The United States and the UAE, which hosts the COP28 climate summit this year, have also been cooperating on climate action.