Saudi Arabia joined the International Maritime Security Construct in a bid to protect shipping in the Arabian Gulf and Strait of Hormuz, its Ministry of Defence said.
Members of the US-led effort have committed troops, planes and ships to accompany and track vessels passing through the Gulf region after a series of attacks and seizures of boats as tension with Iran rises.
Australia, Bahrain and the United Kingdom are also part of the mission. It includes surveillance of the Strait of Hormuz, the narrow mouth of the Arabian Gulf through which a fifth of the world's oil travels, and the Bab Al Mandeb, another narrow strait that connects the Red Sea and the Gulf of Aden off Yemen and East Africa. Smaller patrol boats and other craft will be available for rapid response. The plan also allows for nations to escort their own ships through the region
The US Navy has already sent Arleigh Burke-class guided missile destroyers to chokepoint positions at either end of the Strait of Hormuz. They observe ship traffic and monitor for anything unusual as drones and other aircraft fly surveillance routes overhead.
The US blames Iran for the apparent limpet mine attacks on four vessels in May and another two in June in the Gulf of Oman, near the Strait of Hormuz. Iran also seized a British-flagged oil tanker and another based in the UAE.
It's unclear what role the kingdom will play in the coalition. Bahrain already serves as the headquarters of the US Navy's 5th Fleet.
“The kingdom’s accession to this international alliance comes in support of regional and international efforts to deter and counter threats to maritime navigation and global trade in order to ensure global energy security and the continued flow of energy supplies to the global economy and contribute to maintaining international peace and security,” the Saudi Press Agency said.
The ministry also announced it would reveal more details from its investigation into last week’s attack on Saudi Aramco facilities on Wednesday.
Saturday's strikes on Abqaiq, the world's largest oil-processing plant, and the Khurais oilfield resulted in a slightly over 5 per cent cut to global supplies of crude oil.
The kingdom's Energy Minister, Prince Abdulaziz bin Salman, said that the country's oil output was already 50 per cent restored and would be "back to normal" by the end of the month.
The UAE's Minister of State for Foreign Affairs Dr Anwar Gargash heaped praise on Saudi Aramco for its swift recovery from the attacks.
"Saudi Aramco deserves a certificate of excellency on the professional level and also on the political level," he wrote on Twitter.
"The global economy is grateful and owes Aramco messages of positivity and appreciation," he said, adding that Saudi Arabia was the source for the oil giant's recovery.
Houthi rebels in Yemen claimed they had fired 10 drones at the Saudi installations, but the US insists Iran is to blame.
Wednesday also saw a commitment from French President Emmanuel Macron to assist in the investigation into the attacks.
In a phonecall with Crown Prince Mohammed bin Salman, Mr Macron expressed his "appreciation for the leadership of the Kingdom on its eagerness to stabilise the Middle East", the Saudi Press Agency reported.
"In response to a Saudi request, President Macron confirmed to the crown prince that France will send experts to Saudi Arabia to take part in investigations aimed at revealing the origin and modalities of the attacks," Mr Macron's office said on Wednesday.
In a separate call, British Prime Minister Boris Johnson called for a "firm international stand towards such criminal acts that should not go unpunished," SPA reported.
Washington believes Saturday's attack originated in south-western Iran, a US official told Reuters on Tuesday.
Three officials said the attack involved both cruise missiles and drones, indicating it attack involved a higher degree of complexity and sophistication than initially thought.
Podcast: Saudi oil attack ramifications locally and globally
Any chance of resolving the escalating tensions between the US and Iran at the UN was dashed on Tuesday as Iran’s supreme leader Ayatollah Ali Khamenei said there would be no talks with the US "at any level".
US President Donald Trump gave a fairly restrained response. "I never rule anything out, but I prefer not meeting him," he said.
Mr Trump sent his Secretary of State Mike Pompeo to Saudi Arabia on Tuesday to discuss possible retaliation for the attacks, which wiped out half of the kingdom's oil production capacity.
Vice President Mike Pence announced that Mr Pompeo was on his way to the kingdom to "discuss our response".
"As the president said, we don't want war with anybody but the United States is prepared," Mr Pence said in a speech in Washington.
"We're locked and loaded and we're ready to defend our interests and allies in the region, make no mistake about it," he said, echoing Mr Trump's words on Sunday.
The US appeared to be exploring a number of options to respond to Iranian aggression in the region, including seeking UN intervention in the crisis.
"We do see a role for the UN Security Council to play. Saudi was attacked and it would be appropriate for them to call upon the council. But we first need to gather the releasable information," a senior US official said.
The official did not explain what he meant by "releasable information". The United States has, at times, released previously classified information to buttress its case at the Security Council.
In a blow to Saudi Arabia's recent bid to increase tourism to the kingdom, the US State Department called on American citizens to "exercise increased caution" while traveling to Saudi Arabia, a travel advisory posted on its website said on Wednesday.
US Mission personnel and their families are not permitted to use the airport in Abha without Chief of Mission approval, the note added. Abha airport has been frequently attacked by drones and missiles launched from Yemen, where a Saudi-led coalition has been battling Houthi rebels.