The United States wants to see a strong Saudi Arabia, Defence Secretary Jim Mattis said during talks on Wednesday aimed at reinvigorating the Riyadh-Washington alliance.
Mattis, meeting top officials in the Saudi capital, also hinted that President Donald Trump could visit the kingdom, a longtime US ally which has welcomed Washington's firmer line against common adversary Iran.
"It is in our interest to see a strong Saudi Arabia," Mattis said at the start of talks with Deputy Crown Prince Mohammed bin Salman, the defence minister, pointing to the country's "military security services and secret services."
"What we can do here today could actually open the door possibly to bringing our president to Saudi Arabia," Mattis said.
Mattis, a retired four-star Marine general, earlier met King Salman at Al-Yamama Palace in Riyadh, where he told the king: "It's good to be back."
Mattis commanded troops during the 2003 invasion of Iraq.
He arrived in the kingdom on Tuesday afternoon to listen to Saudi leaders and learn "what are their priorities," an American defence official said earlier.
The United States and Saudi Arabia have a decades-old relationship based on the exchange of American security for Saudi oil.
But ties between Riyadh and Washington became increasingly frayed during the administration of president Barack Obama.
Saudi leaders felt Obama was reluctant to get involved in the civil war in Syria and was tilting toward Riyadh's regional rival Iran.
The kingdom "felt marginalised" during international negotiations on a nuclear accord with Iran, the defence official said.
That deal, signed in July 2015 by the Obama administration, saw the lifting of international sanctions in exchange for guarantees that Tehran would not pursue a nuclear weapons capability.
The Saudis have found a more favourable ear in Washington under Trump, who has denounced Iran's "harmful influence" in the Middle East.
In February, Trump imposed new sanctions on Tehran after a ballistic missile test launch, and in response to its support for Yemen's rebels.
Prince Mohammed told Mattis that Saudi Arabia and the United States are working to counter challenges in the region, including "the malign activities of Iran" and to bring stability "to the most important straits."
The US military is watching Houthi activities along the strategic Bab al-Mandab strait connecting the Red Sea with the Indian Ocean.
Mattis was expected to raise with the Saudis Washington's intentions towards Syria, where Riyadh has aided some rebel groups.
Earlier this month, the US fired cruise missiles against a Syrian government airbase after a suspected chemical bombing of a rebel-held town which Washington blamed on President Bashar al-Assad.
After Saudi Arabia, Mattis travels on Thursday to Egypt and then to Israel on Friday before returning to the Gulf on Saturday for talks in Qatar.