President Barack Obama has arrived in Saudi Arabia for talks with King Salman and other leaders from Gulf Cooperation Council (GCC) countries.
Relations have become strained over the fight against so-called Islamic State (IS) and the nuclear deal with Iran.
US Defence Secretary Ashton Carter is on the trip with the president.
Mr Carter said they would be seeking help with military and naval operations to counter Iran’s “destabilising activities” in the region.
Mr Obama will talks with King Salman on Wednesday and meet the leaders of Kuwait, Qatar, Bahrain, the United Arab Emirates and Oman on Thursday.
He will then travel to the UK and Germany.
Press plays down ‘farewell summit’
While Saudi press hails strong relations with the US, Middle Eastern newspapers in general are playing down Barack Obama’s visit, arguing that he does not have enough time before leaving office to mend strained ties, BBC Monitoring reports.
Saudi-owned Al-Hayat sees the visit as “a farewell summit” for the US president: “Obama will no longer be either useful or relevant to the Gulf states,” it says.
Pan-Arab Al-Arab al-Alamiyah agrees, saying that key issues are “most likely to be passed over to the next US administration, which may be better placed to deal with them”.
Rajeh al-Khoury in Lebanese Al-Nahar says Mr Obama will not be able “to correct his illusions about Iran, but will rather leave behind a lesson about failure”.
Saudi pro-government Al-Riyadh urges the US and Saudi Arabia to “square up to growing mutual challenges that include rebuilding confidence”.
Rim al-Harami in Qatari Al-Raya concurs, saying “the challenges remain but they could be overcome if confidence is regained”.
The US support for the lifting of sanctions against Iran has damaged relations with Saudi Arabia, Iran’s biggest rival in the region.
And a bill that is being considered in the US at the moment could potentially allow American citizens to sue Saudi Arabia over the 9/11 attacks.
The GCC includes Saudi Arabia, Bahrain, the United Arab Emirates, Kuwait, Qatar and Oman.