US Secretary of State Mike Pompeo has held talks with the Saudi king and crown prince after days of mounting tensions following the downing of a US drone last week and after President Donald Trump pulled back from the brink of retaliatory military strikes on Iran.
Iran's naval commander, meanwhile, warned that Iranian forces would not hesitate to act again and shoot down more US surveillance drones that violate Iranian airspace.
The US denies the drone, valued at more than $100 million, violated Iranian airspace. Trump said he backed away from planned strikes after learning that 150 people would be killed but that military action remained an option.
On Monday, Pompeo held separate talks with King Salman and Crown Prince Mohammed bin Salman in the Saudi port city of Jiddah to discuss the escalation with Iran.
Pompeo wrote on Twitter that he had a "productive meeting" with King Salman and discussed "heightened tensions in the region and the need to promote maritime security" in the Strait of Hormuz near the Persian Gulf, through which roughly a fifth of the world's traded oil passes.
From the kingdom, Pompeo will travel to neighbouring United Arab Emirates, another close US ally. The regional stops, made on his way to India, may be aimed at reassuring Washington's Sunni Gulf Arab allies that the White House remains committed to maintaining pressure on Shi'Ite Iran following Trump's last-minute about face, which likely raised questions about US willingness to use force against the Islamic Republic.
In what it says are defensive moves, the US has built up its military presence around the Persian Gulf in recent weeks.
Iran's naval commander, Rear Admiral Hossein Khanzadi issued a warning to Washington that Tehran is capable of shooting down other American spy drones that violate Iranian airspace. Khanzadi spoke Monday during a meeting with a group of defence officials in Iran.
"We confidently say that the crushing response can always be repeated, and the enemy knows it," Khanzadi was quoted as saying by the semi-official Tasnim news agency.
Tensions have been escalating since Trump last year withdrew the US from a global nuclear deal with Iran and re-imposed economic sanctions on Iran. A fresh round of US sanctions is to be announced later on Monday in a bid to force the Iranian leadership into talks.
Iran has decried the US sanctions, which essentially bar Iran from selling its oil internationally, as "economic terrorism."
Before boarding his flight to Saudi Arabia, Pompeo described the sanctions as a way to deny Iran "the resources to foment terror, to build out their nuclear weapon system, to build out their missile program."
The hastily arranged Saudi visit by Pompeo, considered a hard-liner in the Trump administration, and the upcoming stop in the UAE come as both countries have expressed alarm over Iran's military reach.
Saudi Arabia and the US have accused Iran of being behind attacks on oil tankers near the Persian Gulf over the past several weeks, while the UAE has been urging diplomacy to avert a wider conflict.
