Hagel will hold talks with Saudi officials and on Wednesday he will meet Persian Gulf Cooperation Council defense ministers in the first US-PGCC meeting of its kind since 2008.

Hagel's plane touched down in the Red Sea city of Jeddah, ahead of a planned tour that US officials said will also take him to Jordan and Israel.

"This trip will be the secretary's third to the Middle East in just over a year, and it will advance America's regional strategy in that region," Pentagon press secretary Rear Admiral John Kirby said last week.

US officials have struggled to reassure Persian Gulf states, particularly Saudi Arabia, over an interim nuclear deal with Iran that the Saudis worry about it.

Kirby last week said US-PGCC gathering will also focus on coordinating "air and missile defense, maritime security and cyber defense (between two sides)," he said.

After his stop in Saudi Arabia, Hagel will head to Jordan for talks on the raging civil war in its neighbor Syria.

"This visit will highlight the US commitment to the defense of Jordan, where more than 1,000 US personnel are on the ground working closely with Jordanian defense authorities," Kirby said.

Hagel will wrap up his regional tour in Israel for talks with top officials and to discuss efforts to bolster Israel's rocket and missile defenses, Kirby said.

The tour is part of "our effort to work in a coordinated manner with allies and partners across the region to address common security challenges," according to the press secretary.

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