"I think they [North Korea] were very clear that they are willing to implement the February 13 agreement once the other parties implement their part," he said, referring to an agreement reached at six-party talks involving the two Koreas, Russia, Japan, the US and China.
Condemnation and sanctions
"The DPRK (North Korea) mentioned that they are waiting for the lifting of sanctions with regard to the Macau bank."
ElBaradei's visit was the first since inspectors from the IAEA were told to leave North Korea in December 2002.
It withdrew from the nuclear Non-Proliferation Treaty days later.
"With the meetings I understood where they are coming from, what are their concerns and hopes," ElBaradei told reporters.
Under the terms of the February agreement, the Yongbyon reactor, which makes plutonium that can be used in nuclear weapons, must be shut by mid-April in return for an initial shipment of heavy fuel oil.
South Korean Foreign Minister Song Min-soon had earlier said that North Korea had shown no signs of closing the reactor.
North Korea tested what is believed to have been a nuclear device last October, drawing widespread condemnation and UN sanctions.
"There is no indication of a change in the operational condition of Yongbyon," Song told a news conference in Seoul.