NEW DELHI/SINGAPORE: Refiners in India and across Asia are exploring purchases of Iranian oil after the United States temporarily eased sanctions, opening access to cargoes already at sea amid a regional energy crunch.

Indian refiners are preparing to resume imports, with three industry sources saying they are awaiting government guidance and clarity from Washington on payment mechanisms.

Elsewhere in Asia, refiners are assessing whether they can also tap Iranian supplies, traders and sources familiar with the matter said.

The Trump administration on March 20 issued a 30-day waiver allowing the purchase of Iranian oil already in transit, U.S. Treasury Secretary Scott Bessent said. The exemption applies to cargo loaded on or before March 20 and delivered by April 19, according to the Office of Foreign Assets Control. It marks the third such waiver since the war began.

The move could unlock significant volumes of oil. About 170 million barrels of Iranian crude are currently at sea, according to Emmanuel Belostrino, Kpler's senior manager for crude oil market data, with shipments spread from the Middle East to waters near China. Consultancy Energy Aspects earlier estimated 130 million to 140 million barrels in floating storage, equivalent to less than two weeks of Middle East production losses.

The near-closure of the Strait of Hormuz has disrupted flows across the region, forcing Asian refiners to cut operating rates and reduce fuel exports. Asia depends on the Middle East for around 60 percent of its crude supply, making it particularly vulnerable to the disruption.

India, which maintains smaller crude stockpiles than some other major Asian importers, has already moved to secure alternative supplies, including booking Russian oil after earlier temporary sanctions relief.

Iranian oil had largely been sidelined since the United States re-imposed sanctions in 2018 over Tehran's nuclear programme. Since then, China has remained its primary buyer, with independent refiners importing about 1.38 million barrels per day last year, attracted by discounted prices.

However, several challenges remain for buyers considering a return to Iranian crude. Traders pointed to uncertainties around payment channels and compliance requirements, as well as logistical concerns tied to shipments carried on older vessels often associated with the so-called shadow fleet.

"It usually takes some time to work through compliance, administration, and banking, etc., but I guess people will try to work ASAP," a Singapore-based trader said.

Contractual arrangements could also complicate purchases. Before sanctions were reimposed, many buyers sourced crude directly from the National Iranian Oil Company. Since then, much of the trade has shifted to third-party intermediaries, adding another layer of complexity.

The sources declined to be named due to company policies. Beyond China, key buyers of Iranian crude prior to the sanctions included India, South Korea, Japan, Italy, Greece, Taiwan, and Turkey.