Mike Pompeo said the Middle East stops on his way to a previously scheduled visit to India.

US Secretary of State Mike Pompeo arrived Monday in Saudi Arabia for talks on coordinating with the close ally amid mounting tensions with Iran.

Pompeo is expected to meet in the Red Sea city of Jeddah with King Salman and the powerful crown prince, Mohammed bin Salman, before flying for talks in the United Arab Emirates, US officials said.

Both Saudi and Emirati leaders advocate a tough US approach against regional rival Iran, which last week shot down an unmanned US drone, prompting President Donald Trump to order a military strike before changing his mind.

Pompeo, speaking to reporters as he left Washington, called Saudi Arabia and the United Arab Emirates "two great allies in the challenge that Iran presents".

"We'll be talking with them about how to make sure that we are all strategically aligned and how we can build out a global coalition," Pompeo said.

He said the United States sought a coalition "not only throughout the Gulf states but in Asia and in Europe that understands this challenge and that is prepared to push back against the world's largest state sponsor of terror".

His trip comes despite growing controversy inside the United States over the Trump administration's cosy relationship with Mohammed bin Salman after US-based dissident writer Jamal Khashoggi was killed and dismembered in the Saudi consulate in Istanbul last year.

Pompeo used rare emergency powers, citing Iran as a threat, to authorise $8.1 billion in weapons sales to Saudi Arabia and the United Arab Emirates, despite concerns in the US Congress that the arms will go to kill civilians in the devastating war in Yemen.

Pompeo added the Middle East stops on his way to a previously scheduled visit to India.