The White House announced on Thursday that Saudi Arabia’s King Salman will meet with US President Barack Obama in Washington on September 4th to discuss a “destabilizing” Middle East.

White House spokesman Josh Earnest told reporters traveling on Air Force One that the two leaders will discuss Yemen, Syria and steps to counter “Iran’s destabilizing activities in the region.” His visit is timely, coming a few days before the vote in Congress on the nuclear deal with Iran.

Relations between the two countries have been tense lately since Saudi Arabia, a close ally of the US and leader of the Sunni Muslim world, has voiced mixed support for the Obama-led deal with Iran, leader of Shia Islam and considered a rival by Saudi Arabia.

The US has joined efforts with the Saudi-led coalition air attacks against Iran-backed Houthi rebels in Yemen with logistical and intelligence support, but the deal is expected to bolster Iran, removing sanctions and providing them with billions of dollars in US aid.

US Defense Secretary Ash Carter visited Saudi Arabia in July and said that Salman and his defense minister voiced reserved support for the deal, expressing concerns that it needs to be properly implemented.

Obama visited the new Saudi king in January, shortly after the death of his father, King Abdullah bin Abdul Aziz al-Saud. September’s visit will be Salman’s first visit to the US since ascending the throne.

“His visit underscores the importance of the strategic partnership between the United States and Saudi Arabia,” said Earnest, adding that the talks would be aimed at strengthening ties.