U.S. national security adviser Jake Sullivan met Saudi Arabia’s Crown Prince Mohammed bin Salman on Thursday in Jeddah, the White House said, as U.S. officials search for ways to reach a deal normalizing ties between Israel and Saudi Arabia.

U.S. officials have sought for months to reach what would be a historic agreement between the long-time adversaries but the Saudis have been resistant.

President Joe Biden said on CNN in early July that Israel and Saudi Arabia are a long way from a normalization agreement that would involve a defense treaty and a civilian nuclear program from the United States.

Sullivan, who was joined by White House Middle East coordinator Brett McGurk, met bin Salman and senior Saudi officials and discussed “initiatives to advance a common vision for a more peaceful, secure, prosperous, and stable Middle East region interconnected with the world,” the White House said.

The White House statement made no mention of Israel, but a White House official said a possible normalization agreement with Israel was among various topics.

They also discussed efforts to build on the benefits of a truce in the war in Yemen.

Biden has had difficult relations with both bin Salman and Israeli Prime Minister Benjamin Netanyahu.

He has argued to little avail against oil production cuts by the Saudis and tried to persuade Netanyahu to slow the pace of a drive for a judicial overhaul in Israel.

U.S. officials see a potential deal between Israel and Saudi Arabia as possible after the administration of former President Donald Trump reached similar agreements between Israel and Morocco, Sudan, Bahrain and the United Arab Emirates.