SEOUL/TOKYO: Plans for fresh US sanctions to isolate Tehran have sent shudders among Asian governments who fear they will have no way to pay for Iranian crude imports and face rising costs to fuel the region’s growing economies.

At stake is around 1.4 million barrels of oil Iran ships to Asia every day, meeting 10 percent of demand from top buyers China and India. South Korea, Japan and India are scrambling to find ways to keep the oil flowing.

Any restriction on oil supplies from Iran, the world’s fifth-largest crude exporter, could drive up already high oil prices and threaten economies already facing the impact of the euro zone debt crisis.

“This is an issue that could have a big impact on the global economy in terms of crude prices, so our nation will pay close attention to this with grave concern,” said Japanese Chief Cabinet Secretary Osamu Fujimura.

Japan is in talks with U.S. diplomats about a possible waiver to U.S. legislation that would make it more difficult to pay Iran. 

South Korea would also seek an exemption if the bill is signed into law, which U.S. Congress expects to send to President Barack Obama as early as this week.

Existing sanctions do not penalize non-U.S. refiners from buying Iranian crude, but they make it hard for foreign banks to pay Iran  

New U.S. measures would make paying harder still by blacklisting the OPEC member’s central bank.

It is unclear how the U.S. hopes China would cooperate if Washington imposes another round of unilateral sanctions. 

Beijing has previously criticized measures imposed outside United Nations’ sanctions.

China is Iran’s biggest oil buyer, taking over half a million barrels per day, and its top refiner, state-run Sinopec Corp, is trying to obtain more attractive oil contract terms from Iran.

Beijing is Iran’s biggest trade partner but there is no sign Tehran is using oil to keep China sweet.

Tehran is not budging on terms and wants Sinopec and state oil trader Zhuhai Zhenrong Corp to pay more and faster than it has done in 2011.

While Beijing looks to take advantage of political tensions, both Japan and South Korea struggle to balance their close alliance with the United States with their dependence on Iranian oil imports.

At least three Japanese banks, Mitsubishi Financial UFJ Financial Group, Mizuho Financial Group and Sumitomo Mitsui Financial Group, settle crude payments with Iran’s central bank, said Katsunori Nagayasu, chief executive of MUFG.

-- South Korea fall short of demands from Washington

South Korea, the world’s fifth-largest crude importer, wants to keep Iran’s central bank accounts open at two Korean banks, government officials said. Without them, it cannot pay for Iranian oil.

South Korea on Friday imposed new sanctions on Iran, although its moves appeared to fall short of demands from Washington.

South Korea’s finance ministry said it would keep bank accounts held by the Iranian central bank in Seoul open so as not to disrupt crude oil supply from the Persian Gulf nation that supplies almost 10 percent of its oil needs.

According to latest industry data from the Korea International Trade Association, South Korea imported oil and other products worth $10.87 billion between October of 2010 and October 2011 and had exports worth $6.14 billion.

South Korea backed down from an earlier plan to ban Iranian petrochemical imports.

“We plan to suggest to domestic firms that they take cautious measures in their petrochemical product purchases,” the ministry statement said.

South Korea imported $350 million worth of Iranian petrochemicals last year, while exporting $450 million worth of its own petrochemicals to Iran. South Korea’s global trade in petrochemicals last year totaled $49 billion.