United Nations Secretary-General Antonio Guterres called Friday for an independent investigation to establish the facts and who was responsible for attacks on two oil tankers this week in the Gulf of Oman.
The United States blamed Iran for the attacks on Thursday, a charge Tehran rejected.
Amid the rising tensions, Guterres said he was available to mediate if the parties agreed, however he added that "at the present moment we don't see a mechanism of dialogue possible to be in place."
Tehran and Washington have both said they have no interest in starting a war, but this has done little to assuage concerns that the two arch foes could stumble into a conflict.
Guterres said the world cannot afford a major confrontation in the Gulf.
"It's very important to know the truth and it's very important that responsibilities are clarified.
Obviously that can only be done if there is an independent entity that verifies those facts," he told reporters, adding that he believed only the Security Council could order a UN investigation.
UN political affairs chief Rosemary DiCarlo met with Iranian Foreign Minister Mohamed Javad Zarif yesterday on the sidelines of a Shanghai Co-operation Council meeting in Kyrgyzstan, UN spokesman Stephane Dujarric said.
He added that Guterres and his staff had been in contact with many of the countries concerned to tell them of the need to avoid any escalation.
Guterres, who condemned the attacks on the tankers, was speaking yesterday alongside Arab League Secretary-General Ahmed Aboul Gheit after the pair met.
Gheit told reporters that he did not believe an Arab country was "trying to obstruct naval lanes or to shoot itself in the foot by acting the way we have seen in the Gulf of Oman or in the Hormuz Strait."
Oil prices have surged in response to the rising tensions.
China called for all sides to "resolve the conflict through dialogue," while the European Union called for "maximum restraint."
Russia, which has close — if sometimes strained — links to Iran, warned through its foreign ministry against "hasty conclusions."
The oil tankers were 10 nautical miles apart and headed to Asia when they were struck by explosions early Thursday after passing through the Strait of Hormuz some 25 nautical miles off Iran's southern coast.
There was no claim of responsibility for the blasts, which struck both tankers at the waterline.
Iran said its navy rescued several dozen crew members from the two vessels, while the US Navy said it had picked up 21 from the Kokuka Courageous.
Iran's English-language Press TV aired footage of rescued crewmen from the Front Altair, saying they were all in "full health."
The crew of the Kokuka Courageous saw a "flying object" before a second blast on board, the operator's head said yesterday.
The Kokuka Courageous is now safely under tow and heading towards the United Arab Emirates' port of Kalba, south of Fujairah, the ship's operator said yesterday.
Earlier, the Dutch marine engineering firm Boskalis said it had been appointed to salvage the vessel and the other tanker, the Front Altair, operated by Frontline.
"The Kokuka Courageous is stable. Full damage assessments will be carried out, but there is no danger of her sinking and there is no loss of cargo or fuel containment," the statement said.