Kim Yong-Nam blamed Washington for the delayed release of North Korean funds held at a Macau bank, according to Yonhap news agency.

"We are taking steps as agreed upon, but the United States is acting in a two-faced way, causing the delay," he said.

Kim's comment came at talks with visiting former South Korean provincial governor Sohn Hak-Kyu in Pyongyang, Yonhap said.

North Korea has refused to start shutting down its Yongbyon reactor, as pledged in a February 13 multinational agreement, until it receives 25 million dollars which had been frozen in the Macau bank following a US blacklisting.

In an attempt to move the nuclear pact forward, Washington said in March that the funds had been unfrozen. But foreign banks are unwilling to handle the cash as it is seen as tainted.

"The February 13 agreement was made to be implemented, not just adopted as a document," Kim reportedly said.

Denuclearisation was founder of the nation Kim Il-Sung's dying wish, he said, adding the North's nuclear programme was created as a self-defence measure against Washington's "hostile" policy.

Sohn, an independent presidential hopeful, was scheduled to tour industrial facilities and exchange views on inter-Korean economic cooperation and the nuclear dispute during a four-day trip to North Korea that ends on Saturday, Yonhap said.

The former governor, who defected from South Korea's conservative opposition Grand National Party in March, remains a distant third in polls.