TOKYO, April 10 (RIA Novosti) - Japan's foreign minister said Tuesday North Korea could fail to meet the deadline for its initial denuclearization commitments under a breakthrough deal with the six negotiators.

Pyongyang agreed to close its reactor under international control by April 14 at a February round of six-nation talks in exchange for economic and political incentives. But the Communist nation refused to act on the commitment in mid-March over delays in releasing its $25 million frozen in a Macao bank under U.S. sanctions.

"Whether they [North Korea] will be able to take measures by April 14 and meet the 60-day deadline remains a complicated issue," Taro Aso said.

North Korea's accounts in Banco Delta Asia in China's administrative region have been unfrozen, but the parties involved have so far failed to find a way of returning the money to North Korea, as foreign banks have refrained from working with BDA after Washington banned American financial institutions from conducting any transactions with the bank.

"Even if a bank had been chosen to receive the North Korean funds, the Foreign Ministry [of Japan] doubts the problem would be resolved the same day. It is a complicated issue," Aso added.

Assistant Secretary of State for East Asian and Pacific Affairs Christopher Hill, now in Japan, said he hoped a solution would be found in the next few days.

Earlier Tuesday, Japan made a decision to extend economic sanctions against North Korea for six months in a bid to push the reclusive regime to further talks on its nuclear program.

Japan halted imports and closed its ports for North Korean ships following Pyongyang's nuclear bomb tests in October 2006. Tokyo earlier warned the impoverished nation about additional sanctions over lack of progress in talks on Japanese citizens abducted by Korean security services in the 1970-1980s.

Pyongyang has acknowledged the abduction of 13 citizens, saying five of them have been repatriated and the other eight have died. But Tokyo insists more of its citizens are still in North Korea.