SEOUL — South Korea said Wednesday that it had failed to reach a compromise with the United States on its civil nuclear energy program, forcing the two allies to delay the deadline for a deal by two years.
Secretary of State John Kerry had called for an agreement before the planned summit between President Obama and his South Korean counterpart, Park Geun Hye, on May 7. But the allies’ differences remained deep over South Korea’s demand that the US ban on enriching uranium and reprocessing spent nuclear fuel be lifted. The United States had South Korea commit itself to the ban in a treaty signed in 1972 when Washington transferred nuclear material and technical expertise to help South Korea’s nuclear energy industry.
As the allies negotiated to revise the treaty, which expires in March 2014, South Korea demanded the ban be lifted so it can enrich uranium to make nuclear fuel, which it now imports. It also wanted to reprocess spent nuclear fuel to reduce its almost full nuclear waste storage and turn the waste into fuel for the next generation of reactors it develops.
But the same technologies are also used to make material for nuclear weapons. Washington feared that allowing South Korea to engage in either enrichment or reprocessing technologies would undermine its global efforts to curb nuclear proliferation. That would also complicate Washington’s diplomacy to persuade North Korea and Iran to give up their nuclear programs, US officials said.
“We are at a delicate moment with respect to the situation with the North, and we are also dealing with Iran and are very concerned at this time about not having any ingredients that could alter our approach with respect to either of those,’’ Kerry said in the South Korean capital, Seoul, on April 12.
But Park made securing US concessions on the issue one of her top campaign pledges for her December election. She has repeatedly appealed for such concessions since taking office in February.
Her foreign minister, Yun Byung Se, said the negotiations will be an important test of ‘‘trust’’ between the allies. That would also complicate Washington’s diplomacy to persuade North Korea and Iran to give up their nuclear programs, US officials said.
The South has denied any intention of developing nuclear weapons. But a few members of the South Korean governing party grabbed Washington’s attention by urging their government to consider building nuclear weapons to counter North Korea’s nuclear threat.