President Bush has cautiously welcomed North Korea's pledge to give up its nuclear weapons.
The president says the agreement, reached at six-party talks in Beijing, is a positive step.
"Five nations working with North Korea have come up with a formula, which we all hope works," said Mr. Bush. "Five nations have spoken, and said it is not in the world's interest that North Korea has a nuclear weapon."
The agreement ended a two-year stalemate in negotiations involving diplomats from North Korea, the United States, China, South Korea, Japan and Russia.
Pyongyang pledged in principal to give up all its nuclear programs, rejoin the nuclear Non-Proliferation Treaty, and permit international inspections. In exchange, the other participants in the talks said they are willing to provide energy assistance, and security assurances.
It was an unexpected agreement, and relatively short on specifics, such as the type and cost of energy aid to be provided. Details will be worked out when the six parties resume talks in November. But the president makes clear he sees the deal as an important first step in resolving the dispute about North Korea's nuclear ambitions.
"And, now, there is a way forward," added Mr. Bush. "And, part of the way forward is for the North Koreans to understand we are serious about this, and we expect there to be a verifiable process."
The White House has stressed verification is key. Officials here remain somewhat skeptical of any commitments made by North Korea, noting Pyongyang walked away from pledges made in the early 1990's to freeze its nuclear program.
During a brief session with reporters, President Bush left no doubt that the other participants in the six-party talks will be watching closely to see if North Korea follows its words with deeds.
"They have said, in principle, that they will abandon their nuclear weapons programs, and what we have said is 'great, that is a wonderful step forward, but now we have got to verify whether or not that happens,'" said Mr. Bush.
Earlier, White House Spokesman Scott McClellan said implementation is key, and stressed North Korea must dismantle its nuclear programs and come in full compliance with the nuclear Non-Proliferation Treaty and the International Atomic Energy Agency (IAEA).