The Chinese government has said it cannot confirm South Korean reports of unusual activity at North Korea's Yongbyon nuclear facility, and indicated a dispute over North Korean bank accounts in Macau has yet to be resolved. Daniel Schearf reports from Beijing.

Spent nuclear fuel rods at a nuclear facility in Yongbyon, North Korea (File)

South Korean media reports Tuesday said intelligence satellite imagery shows new activity around North Korea's main Yongbyon nuclear reactor. The news reports say the activity suggests Pyongyang may be preparing to shut down the facilities as it agreed to in February.

China's Foreign Ministry spokesman Liu Jianchao, however, says he has noted the reports but can not confirm whether a shutdown is occurring.

"The concrete situation is not clear," said Liu. "On principle, we hope all sides can abide by the commitments they agreed to in the February 13th joint document and implement relevant activities and obligations."

North Korea in February agreed to seal its nuclear reactor and allow inspectors back into the country within 60 days in exchange for aid and diplomatic benefits. The deal is part of international efforts to end Pyongyang's effort to build nuclear weapons.

But Pyongyang failed to meet the deadline on Saturday, saying it needed to confirm the transfer of $25 million from North Korean accounts in a Macau bank.

Liu indicated the banking issue has not yet been resolved.

"On this issue it appears the thinking of relevant parties is becoming closer …. But, there are still some specifics on which relevant countries have their concerns," said Liu. "It needs to be further clarified and confirmed. We hope the process can be concluded soon."

Macau authorities froze the accounts in 2005 because of U.S. concerns the bank was helping North Korean money laundering and counterfeiting activities.

The U.S. investigated the bank and declared it guilty but agreed North Korea could have the money back if it returned to negotiations on its nuclear programs. Washington says the North Korea can withdraw the money at any time.

The transfer has since been stalled due to problems finding a bank that will handle the fund transfer.