Iran rejected a proposal to evenly divide control of the Strait of Hormuz, jeopardizing hopes that Tehran and Washington would quickly resume negotiations to end the war.
Oman, which sits opposite Iran across the strait, suggested a temporary plan to establish even lanes of control, but Tehran demanded Tuesday that it take the lion's share of the waterway critical to the flow of the world's oil supply, one of its top diplomats said.
A lull in fighting between the U.S. and Iran since Friday has prompted a new push for mediation, which included a proposed 10-day ceasefire plan.
But officials in mediating countries said they were incensed by Tehran's rejection of the Oman plan. Tehran will only move to the next stage of negotiations if Oman agrees to Iran's Hormuz plan, said Iran's deputy foreign minister, Kazem Gharibabadi.
Oman had proposed an equal division of transit routes between the two states. Gharibabadi said that plan "doesn't address Iran's security concerns."
Tehran countered with a plan under which one direction of traffic would pass through solely Iranian waters and part of the opposite lane would also be Iranian, Gharibabadi told state television.
"The inbound shipping lane must be entirely under Iran's control, while part of the outbound lane may remain under Oman's control," Gharibabadi said. "If they accept this proposal, we will move on to the next stage."
In talks with Oman, Tehran insisted on retaining full control of the waterway because U.S. military supplies used to attack its territory transited the strait, an Iranian official said Monday.
Iran sits on the northern side of the narrow waterway, while Omani territory occupies the top of the point of land jutting out of the southern shore.
Before the war, roughly 100 ships passed freely through the Strait of Hormuz each day, without the payment of any fees. Tankers carried some 20 million barrels of oil and petroleum products a day, about one-fifth of global oil consumption.
Even a temporary arrangement would have left unresolved the long-term management of Hormuz. Omani officials have proposed establishing a regional consortium that would oversee maritime security, search-and-rescue operations and other cooperation, said officials familiar with the matter. The proposal, backed by Gulf states, includes voluntary funding from regional countries and the shipping and oil industries, the officials said. Iran insists that in the long-run, any ship passing through the waterway pay mandatory fees for maritime services, a plan rejected by Gulf states and the U.S.
Under another plan proposed by mediators, Iran, the U.S. and Oman would coordinate on navigation in the waterway, according to senior regional officials.
Before the latest round of talks between Oman and Iran, Muscat angered the military in Tehran when, without Iranian approval, it set up a U.S.-backed shipping corridor that hugged the Omani coastline. The dispute prompted Tehran to resume attacks on ships transiting the strait without its permission, which in turn prompted the U.S. to launch several rounds of strikes against Iranian military targets.
Mediators say Iran's rejection of the Omani proposal has undermined their attempts to resuscitate a preliminary peace deal signed by Tehran and Washington last month.
Mediators from Pakistan, Qatar, Turkey and Egypt are still trying to get Iran and the U.S. to resolve ambiguities in that agreement, including language that Iran has interpreted to say it has the right to control the strait and charge fees for its use, a position the U.S. opposes.
