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

"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," Obama said in Riyadh on Thursday after the summit with the Gulf Cooperation Council (GCC).


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"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 they have continued to work together on shared concerns such as the wars in Syria, Iraq and Yemen.

"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.

Relations between Washington and Gulf states allies have been far from smooth recently [AP]

The GCC states believe the US has pulled back from the region during Obama's presidency, 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.

Obama came to Saudi Arabia hoping to allay Gulf states' fears over Iranian influence and encourage them to ease sectarian tensions in an effort to confront the threat posed by armed groups such as Islamic State of Iraq and the Levant (ISIL).

"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.

United against ISIL

Obama said that the US and its Gulf allies were united in the war against ISIL.

"We remain united in our fight to destroy ISIL or Daesh which is a threat to all of us," Obama told reporters, after talks with leaders of the GCC, consisting of Saudi Arabia, Qatar, Kuwait, Bahrain, the United Arab Emirates and Oman.  

Obama said that the GCC countries pledged to increase their contributions to battling ISIL, which controls large territory in Syria and neighbouring Iraq.

"We will continue to support Iraq as it liberates and stabilises towns and cities from ISIL control," he said,

The regional conflicts in Syria, Yemen, Libya and Iraq were discussed during the meeting in Saudi capital.

Source: Al Jazeera and agencies