The support was given to South Korean Prime Minister Kim Hwang-sik during his just-concluded trips to Oman and the United Arab Emirates, his office said, Yonhap News Agency reported.
Robert Einhorn, the U.S. State Department special adviser for non-proliferation and arms control, urged Seoul Tuesday to cut its purchases of Iranian oil in line with Washington's new sanctions against Tehran's nuclear program.
Iranian currently accounts for 10 percent of South Korea's oil imports.
Kim secured oil guarantees in the event of any political instability in Iran affecting Seoul's oil supply, Yonhap reported. His office said Oman's Sultan Qaboos bin Said al-Said promised to help South Korea if it had difficulty in importing crude, and Abu Dhabi Crown Prince Sheik Mohammed bin Zayed al-Nahyan offered to provide South Korea with crude oil first in any energy market crisis.
Oman accounted for 2 percent of South Korea's oil imports of 846 million barrels last year, while the UAE accounted for 10 percent, the report said.
In his talks with South Korean officials, Einhorn assured Washington would help South Korea minimize any fallout from the sanctions, the report said.
"We are urging all of our partners to help us, work with us in putting more pressure on the government of Iran to get them to negotiate seriously," he was quoted as saying.