are very aware of the fact that this is a step-by-step process, with many steps to come," Hill said. Pyongyang agreed to abandon its nuclear program in exchange for access to frozen funds at a Macau bank. The funds were frozen after the U.S. blacklisted the bank for allegedly assisting North Korea in its illicit activities.

Hill was in Tokyo to report on recent steps to restart talks with Pyongyang, such as unfreezing the funds, which were finally transferred to North Korean accounts at a Russian bank.

U.S., China and Macau authorities had earlier agreed to the release of the money, but the process hit a snag when no international bank proved willing to accept the tainted North Korean funds.

However, Hill noted that the successful transfer of the funds was just the latest step on a long road.