CIA Director John Brennan is accompanying President Obama to Saudi Arabia, a detail the White House didn't disclose in the lead up to the visit to the key U.S. ally in the region.

As the president and his entourage arrived in Riyadh and disembarked from Air Force One, a White House pool reporter spotted Brennan getting into a van driving to Erga Palace for a meeting between Obama and King Salman and senior U.S. and Saudi officials.

The U.S. delegation also included Defense Secretary Ashton Carter, National Security Adviser Susan Rice, Deputy National Security Adviser Ben Rhodes, U.S. ambassador to Saudi Arabia Joseph Westphal, and Lisa Monaco, assistant to the president for homeland security and counter-terrorism, among others.

Brennan's presence in Riyadh is particularly significant considering his announcement last week that the CIA and its regional partners have new plans to provide more powerful weapons to moderate rebels in Syria to help counter Russia's efforts to bolster Syrian leader Bashar Assad's hold on power. The Saudis have long supplied weapons and ammunition to several opposition groups in Syria, and have urged the U.S. to do more to help them.

The topic will undoubtedly be discussed during a summit of Gulf countries set to take place Thursday as part of Obama's visit to Riyadh.

It also stands out considering the controversy over whether the Obama administration will declassify the final 28 pages of 9/11 Commission's report, amid claims those pages could reveal a Saudi government role in the attacks.

Peppered with questions from reporters about it this week, the White House stressed Tuesday that the independent commission that investigated the attacks determined that the Kingdom of Saudi Arabia had no culpability.

The report stated that there was "no evidence that the Saudi government as an institution or senior government officials" were involved with or supported the hijackers, 15 of the 19 of which were Saudis. "That is an important fact," White House spokesman Josh Earnest said.

No one is "burying information" about Saudi government complicity in the deadly plot, Earnest added.

Just hours before leaving on the trip to Riyadh, Earnest also cheered new GOP opposition to a bill giving 9/11 victims the right to sue Saudi Arabia. Speaker Paul Ryan, R-Wis., indicated his worries about the bill Tuesday and Sen. Lindsey Graham said he was so concerned he placed a hold on the measure.

One day earlier, Earnest hinted Obama would veto the bill, co-sponsored by Sens. John Cornyn, R-Texas, and Chuck Schumer, D-N.Y., over concerns that it would unravel countries' sovereign immunity, and pose larger legal consequences for individual Americans if that immunity is lost.

Saudi Arabia has threatened to sell roughly $750 billion in U.S. assets if the Cornyn-Schumer bill passes and becomes law.