US Secretary of State Marco Rubio (L) meets with Saudi Arabia's Crown Prince Mohammed bin Salman in Riyadh. AFP
The talks in Riyadh began just before 6:00 pm (1500 GMT), a State Department official said.
Rubio was expected to discuss President Donald Trump's widely criticised plan for the United States to take control of the Gaza Strip and move its Palestinian inhabitants elsewhere.
He was accompanied by National Security Advisor Mike Waltz and special Middle East envoy Steve Witkoff.
Witkoff had teamed up with an outgoing envoy from former president Joe Biden to push the ceasefire deal between Israel and Hamas which took effect on January 19 -- a day before Trump took office.
Just after he arrived in Riyadh, Rubio met his counterpart Prince Faisal bin Farhan but the two officials did not comment to reporters.
Washington said Rubio, Waltz and Witkoff would on Tuesday meet a Russian delegation including Foreign Minister Sergei Lavrov in Riyadh, ahead of a future meeting on Ukraine between Trump and Putin in the Saudi capital.
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