Riyadh: The United States will deter and confront aggression against Gulf Arab states, who continue to have concerns about threats from Iran, President Barack Obama said after meeting their leaders to iron out strains in their alliance.

Obama came to Saudi Arabia hoping to allay Gulf states’ fears over Iranian influence and encourage them to douse sectarian tensions in an effort to confront the threat posed by terrorists like Daesh.

“I reaffirmed the policy of the United States to use all elements of our power to secure our core interests in the Gulf region and to deter and confront external aggression against our allies and our partners,” he said in Riyadh on Thursday after the summit with the Gulf Cooperation Council (GCC).

The president added in his statement that all the leaders were committed both to the fight against Daesh and to de-escalating regional conflicts, and addressed the Gulf countries’ concerns on Iran.

“Even with the nuclear deal we recognise collectively that we continue to have serious concerns about Iranian behaviour,” he said.

There was no denying the strains that have afflicted ties between Washington and its Gulf partners, though, even as they have worked together on shared concerns such as the wars in Syria, Iraq and Yemen, however.

“What is true between the United States and the GCC, as is true with all of our allies and friends is that at any point of time there are going to be differences,” Obama said.

Footage and photographs aired on state media showed the leaders at a large circular table under a chandelier, with Obama sitting with King Salman on his left.

Years of frustration among Gulf countries, aggravated by more recent stumbles, may have made Saudi Arabia and its regional allies less receptive to Obama on his fourth and most probably final trip to the kingdom.

Most of the GCC states have been bitterly disappointed in Obama’s presidency, during which they believe the United States has pulled back from the region, giving more space to Iran.

They were also upset by Obama’s remarks in a magazine interview that appeared to cast them as “free-riders” in US security efforts and urged them to “share” the region with Tehran.

“On the core issues, there’s agreement about where we want to go,” Ben Rhodes, Obama’s deputy national security adviser, told reporters at a briefing in Riyadh.

He said strains in ties in recent years reflected differences over tactics rather than goals. “This summit allows us to align our approaches and strategies,” he said.

Rhodes said a two-hour meeting with Saudi Arabia’s King Salman on Wednesday was the longest the two leaders had shared and included a “very open and honest discussion” that included issues which were a source of tension, without specifying them.

“I think they both agreed that it was good to essentially have this opportunity to clear the air,” he said.

The American president has said he wants Gulf allies to offer more democratic reforms and improve human rights, and he discussed that with King Salman on Wednesday.

Adding to tensions is a bill proposed in US Congress to lift Riyadh’s immunity if any Saudi officials are found to have been involved in the September 11, 2001, attacks. Obama has said he opposes the bill because it could lead to cases directed against the United States in foreign courts.

The United States remains deeply enmeshed in Gulf security, cooperating closely with the states to strengthen their armed forces and share intelligence aimed at countering Islamist militant groups.

“The GCC countries have extensively cooperated with us on counter terrorism, curbing the financing of terrorist activities,” Obama said after the summit.

The underlying strong relationship was underscored in a cartoon published on Thursday in the pan-Arab daily Asharq Al Awsat, owned by King Salman’s branch of the Al Saud ruling family.

It showed what appeared to be an cleric in black turban and robes, sweating with alarm as he read a newspaper headlined “Obama in Riyadh”.

All the Saudi newspapers published several pages of photographs of Obama’s meetings with Salman and other princes.

In keeping with a noticeably low-key approach by Saudi Arabia’s government, however, neither that photo opportunity, nor the GCC meeting’s opening statements, were broadcast on live television, as has often been the case before.