In a November 24 deal with six major powers, Iran won access to $4.2 billion in oil revenue from a number of countries that has been frozen abroad. The funds will be paid in eight transfers on a schedule that started with a $550 million payment by Japan on February 1.
South Korea is set to make two payments in March totalling $1 billion, banking sources said on Wednesday, and the next scheduled tranche of oil funds would come on April 10.
"We are ready to make a payment as soon as banking modalities are worked out," Rae told Reuters.
The finance ministry is working out the banking channel that will be used for the payments, he said.
Tehran is allowed to receive $450 million from India on March 1 if it satisfies targets set down in the November deal, according to the payment schedule. It can then receive two further tranches of $550 million on March 7 and April 10 without having to meet further conditions.
Payments from April 15 will be contingent on confirmation that Iran has kept its commitment to dilute all of its 20 percent enriched uranium to no more than 5 percent enriched uranium.
Last month India sharply raised imports from Iran, but total shipments from April through January, the first 10 months of this fiscal year, averaged about 201,000 barrels per month, reflecting a decline of 26 percent from a year ago.
Since February last year, Indian refiners have been withholding 55 percent of the money owed Iran after a previous payment mechanism through Turkey's Halkbank was stopped under pressure from sanctions.
The refiners now owe roughly $3 billion for Iranian crude, and the $1.5 billion in scheduled payments will clear around half of that.
Meanwhile, they have been depositing the other 45 percent in rupees in UCO Bank, which Tehran has been using for importing goods from New Delhi.