The agency's source said the chances of that happening are "high."
Last week, a delegation of inspectors from the International Atomic Energy Agency (IAEA) and Pyongyang reached an understanding on shutting down North Korea's main Yongbyon reactor. IAEA experts are expected to arrive in North Korea July 12-14 to monitor the closure of its nuclear facilities.
Chinese Foreign Minister Yang Jiechi visited Pyongyang to discuss the resumption of six-party talks.
But Japan said Tuesday six-party negotiations were unlikely to go ahead in early July as Washington had hoped.
"The IAEA Board of Governors will hold a session July 9 and the [six-party] negotiations will start after the session," Japanese Foreign Minister Taro Aso said. "All of this will take several weeks, and therefore it is unlikely that the talks will be held in early July."
He added that the participants in the negotiations initially need to discuss the results of last week's nuclear watchdog inspection, which was led by IAEA Nuclear Safeguards Director Olli Heinonen.
The delegation made a two-day trip to the Yongbyon nuclear complex, about 100 kilometers (60 miles) north of the capital, the first visit by UN officials since 2002, when North Korea expelled inspectors and subsequently withdrew from the Nuclear Non-Proliferation Treaty.
At the previous round of talks in Beijing between North and South Koreas, China, Russia, Japan and the United States, Pyongyang agreed to close down the reactor and to let UN inspectors monitor its closure, but only after funds frozen at the request of the U.S. in a Macao bank had been transferred.
The money, totaling around $25 million, was transferred to Pyongyang two weeks ago via a regional Russian bank.
Pyongyang conducted its first nuclear bomb tests in October 2006. The country agreed to close down the reactor in exchange for international aid.