Iran said South Korea has begun to release some of the $7 billion it has trapped in the Asian country because of U.S. sanctions, progress toward ending a spat linked to the seizure of an oil tanker.

Seoul will free $1 billion in an “initial step” that could eventually resolve the dispute, Iranian government spokesman Ali Rabiei said at a news conference in Tehran on Tuesday. Iran has said it wanted to use the funds to purchase medicines during the coronavirus outbreak.

South Korea’s Yonhap News Agency reported the unfreezing of the funds would involve consultations with “related countries,” including the U.S., citing the Foreign Ministry in Seoul.

Rabiei said talks are also underway with Japan, Iraq, and Oman to release Iranian funds stuck in those countries.

International banks refused to handle Iranian funds for fear of running foul of U.S. sanctions, making it impossible for Tehran to access money that accumulated in overseas deposits from energy exports.

Iranian officials have said that South Korea alone is holding between $7 billion and $10 billion in oil payments, and in January Rabiei linked his country’s seizure of the South Korean-flagged Hankuk Chemi vessel in the Persian Gulf to the frozen assets.