Pompeo on tour to find global coalition against Iran

US Secretary of State Mike Pompeo is touring the Middle East and Asia looking to build a global coalition against Iran, following a week of crisis that saw the United States pull back from the brink of a military strike on Iran.

Pompeo spoke as he left Washington for Saudi Arabia, then United Arab Emirates. The Sunni Arab allies are alarmed by Shiite Iran's increasing assertiveness and are working to limit its influence in the region. His stops in Jeddah and Abu Dhabi were hastily arranged late last week as additions to a trip to India from where he will join President Donald Trump in Japan and South Korea. But they were not announced until immediately before his departure in a sign of fast-moving and unpredictable developments.

"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, a coalition not only throughout the Gulf states, but in Asia and in Europe, that understands this challenge as it is prepared to push back against the world's largest state sponsor of terror," Pompeo said about Iran.

But even as Pompeo delivered his tough talk, he echoed Trump and Vice President Mike Pence in saying the US is prepared to negotiate with Iran, without preconditions, in a bid to ease tensions. Those tensions have been mounting since Trump last year withdrew the US from a global nuclear deal with Iran and began pressuring Tehran with economic sanctions. A fresh round of Iran sanctions is to be announced on Monday in a bid to force the Iranian leadership into talks.

"They know precisely how to find us," Pompeo said.

It was a week of topsy-turvy pronouncements on US policy toward Iran that careened between the bellicose, the conciliatory and back again after Iran shot down an American military drone and boasted it would not bow to Washington's pressure.

Trump initially said Iran had made a "very big mistake" and that it was "hard to believe" that shooting down the drone on Thursday was not intentional. He later said he thought it was an unintentional act carried out by a "loose and stupid" Iranian and called off retaliatory military strikes against Iran. On Saturday, Trump reversed himself and claimed that Iran had acted "knowingly."

But Trump also said over the weekend that he appreciated Iran's decision to not shoot down a manned US spy plane, and he opined about eventually becoming Iran's "best friend" if Tehran ultimately agrees to abandon its drive to build nuclear weapons and he helps the country turn around its crippled economy.

It comes as Iran-aligned Houthi rebels hit the carpark of Saudi Arabia's Abha airport, about 200 kilometres north of the Yemen border, with a drone, killing one person and injuring dozens.

The Houthis have stepped up missile and drone attacks on Saudi cities in the past month, adding to tensions between US-ally Saudi Arabia and Iran. Riyadh accuses Iran of supplying the Houthis with the weapons, which the Houthis deny.

Then Trump's national security adviser, John Bolton, stepped in Sunday with a blunt warning from Jerusalem, where he was travelling. Bolton said Iran should not "mistake US prudence and discretion for weakness" after Trump called off the military strike. Trump said he backed away from the planned strikes after learning that about 150 people would be killed, but he said the military option remained.

A longtime Iran hawk, Bolton emphasised that the US reserved the right to attack at a later point.