RIYADH (AFP) - US President Barack Obama arrived in Saudi Arabia for a two-day visit on Wednesday (April 20) hoping to ease tensions with Riyadh and intensify the fight against extremists.
He also seeks to focus discussions on efforts to end wars in Syria and Yemen.
Dressed in a grey suit, Obama emerged at 1.14pm (6.14pm Singapore time) and descended the steps of Air Force One onto a red carpet at the Saudi capital's King Khalid International Airport.
Prince Faisal bin Abdulaziz, the governor of Riyadh, greeted him.
Unusually, Saudi state news channel Al-Ekhbaria did not broadcast Obama's arrival, as it had done during his last visit - more than a year ago - to pay respects after the death of King Salman's predecessor King Abdullah.
Tensions between Riyadh and Washington have increased sharply due to what Saudi Arabia sees as Obama's disengagement from the region and tilt towards its Shi'ite rival Iran.
Obama is to hold afternoon talks with Salman, 80, who has presided over a more assertive foreign policy since acceding to the throne.
On Thursday, the president will attend a summit of all six Gulf Arab states, joined by Defence Secretary Ashton Carter and Secretary of State John Kerry.
They will gather in an atmosphere of bitterness with regional leaders offended by Obama's tone and actions, particularly what they see as his reluctance to get involved in Syria and other regional problems, as well as his tilt towards Iran.
The Sunni Gulf monarchies are worried that the lifting of international sanctions against Iran in January under a landmark nuclear deal with major powers led by the United States will embolden it to adopt a more assertive foreign policy across the region.
Mustafa Alani, a senior adviser to the Gulf Research Centre, said Obama's presidency has been "100 per cent negative" for the region, a legacy of "keeping his distance".
But the White House has emphasised the strength of an alliance that has endured more than 70 years, seeking to minimise the frictions.
"There have always been complexities in the US-Saudi relationship. There's been a core to that relationship in which we cooperate on shared interests like counterterrorism," said Ben Rhodes, a close adviser to Obama, who is in the final months of his mandate.
Saudi-US ties are founded on an exchange of oil for security.
"The Saudis are frustrated. They have the impression, probably rightly so, that the White House does not really understand their concern of the Iranian threat", said Lori Plotkin Boghardt, of the Washington Institute for Near East Policy.
Saudis reacted with outrage to comments by Obama published in the April edition of US magazine The Atlantic.
He said the Saudis need to "share" the Middle East with their Iranian rivals, saying that competition between Riyadh and Teheran has helped to feed proxy wars and chaos in Syria, Iraq and Yemen.
Obama spoke of "free riders", suggesting that certain states had not assumed their share of responsibility for regional security.
"I think the US has had long, longstanding concerns about the way the Saudis are behaving in the region. And this president has been more vocal than any about raising that", said Frederic Wehrey, of the Middle East Programme at the Carnegie Endowment for International Peace in Washington.
Also clouding this visit is congressional draft legislation that would potentially allow the Saudi government to be sued in American courts over the Sept 11, 2001 attacks on the United States.
Nearly 3,000 people were killed.
Fifteen of the 19 hijackers were Saudi citizens but no official Saudi complicity in the Al-Qaeda attacks has been proven.
The kingdom has never been formally implicated.
Saudi Arabia has reportedly warned it could sell off several hundred billion dollars' worth of American assets if the bipartisan Bill passes.
On the eve of his departure from Washington, Obama stated his opposition to the draft legislation.
He hopes the talks in Riyadh will concentrate on the fight against the Islamic State in Iraq and Syria (ISIS) group of Sunni extremists, and how to end the conflicts in Syria and Yemen.
Saudi Arabia has assigned warplanes to a US-led coalition fighting ISIS in Syria.
It also leads a separate Arab military coalition that for 13 months has supported Yemen's government in its battle against Iran-backed Shi'ite Huthi rebels.
Amnesty International urged Obama to place human rights at the centre of his discussions. It said opposition voices in the Gulf are systematically "stifled" under the cover of national security.