The US initially missed the deadline to unblock the funds.
Missed deadline
But Washington says authorities in Macau have now released them and has urged North Korea to abide by the denuclearisation agreement reached by the two Koreas, China, Japan, Russia and the United States in Beijing.
North Korea, which conducted its first nuclear test last October, said it would check whether it could access the funds and promised to start scrapping its nuclear  programme once it confirmed that it could access the money.
In Washington, US officials said Friday that North Korea was virtually certain to miss the weekend deadline, although they added this would not necessarily lead to a collapse of the deal.
Song Min-Soon, the South Korean foreign minister, said that as long as all sides remain committed, "it's important not to be bound to the date but to carry out the agreed steps in a stable way".
US officials and experts say the process of shutting down a reactor and having UN nuclear inspectors verify it would probably take several days.
Christopher Hill, the US negotiator in the nuclear talks, said the US "not indifferent to missing a deadline".
He told reporters: "I don't want to put a date or an hour, but another month is not in my constitution."