SEOUL, April 5 (Yonhap) -- South Korea and the United States will resume formal negotiations aimed at revising a bilateral civilian nuclear accord shortly after U.S. Secretary of States John Kerry visits Seoul next week, an official said Friday.

Kerry will arrive in South Korea on April 12 for talks with South Korean Foreign Minister Yun Byung-se and the nuclear accord is expected to be a major agenda item at the Yun-Kerry meeting.

"Formal negotiations will be resumed after Secretary Kerry visits Seoul," the foreign ministry official said on the condition of anonymity.

The 1974 agreement bans Seoul from reprocessing spent fuel because it could yield plutonium that could be used to build atomic bombs. Now Seoul wants Washington to allow it to use a proliferation-resistant technology for enriching uranium and reprocessing spent atomic fuel.

Washington has been reluctant to do so apparently because of proliferation concerns.

After holding talks with Yun in Washington this week, Kerry said he was "very hopeful" that the issue could be resolved before South Korean President Park Geun-hye visits Washington in early May for a summit with U.S. President Barack Obama.

The remarks by Kerry spawned media speculation that Seoul and Washington could reach a deal on the issue ahead of Park's visit to the U.S.

But South Korean officials played down the possibility, saying no deadline has been set for the negotiations.

Upon returning Friday from Washington, Yun told reporters at the foreign ministry in Seoul that he plans to hold next week's talks with the aim of creating a "mutually beneficial and advanced accord."

For a revised accord to be approved by the U.S. Congress, both sides must conclude negotiations by this summer, officials said.