But President Bush's options are also limited, officials acknowledge. China has been unwilling to participate in any economic embargos. Military action to halt North Korea's declared efforts to build its nuclear arsenal has been ruled out as too risky, and virtually impossible while American forces are tied up in Iraq.
Meanwhile, Mr. Bush has been resisting pressure from China and South Korea to improve an offer to the North Koreans he made in June 2004. To avoid failure at the talks, he may have to decide whether to make explicit concessions, including the promise of eventual normalization of relations with a nation that just two months ago he said was run by a "tyrant" who puts dissidents in "concentration camps."
In interviews in Washington in recent days, officials have said they fear three major stumbling blocks to an agreement. The first is the question of whether North Korea is willing to negotiate away all elements of its nuclear program. The Bush administration is still sharply divided over whether North Korea would fully cooperate. True disarmament would include turning over any existing nuclear weapons, dismantling the plutonium-manufacturing facilities it has acknowledged -- centered at a huge nuclear complex at Yongbyon, north of the capital -- and leading inspectors to what the United States charges is a second, secret nuclear program.
That second program, American officials have charged, uses uranium technology provided by A.Q. Khan, the Pakistani scientist who set up an illicit nuclear network and made more than a dozen trips to North Korea.
"He's said a lot about what he sold them," a former intelligence official said recently, "and the president isn't going to reach any agreement that doesn't involve turning over all of that, too." But North Korea, after initially seeming to acknowledge its uranium program when presented with the charges in 2002, has now denied its existence.
The second probable stumbling block is timing, American officials say. North Korea does not trust the United States to deliver on its promises if it gives up its nuclear program first. Mr. Bush has said publicly that he does not trust Kim Jong Il, the North Korean leader.
The third potential problem is verification. North Korea has never allowed inspectors to move freely, and threw out the International Atomic Energy Agency on New Year's Day 2003. A result is that American officials are uncertain where the North may be hiding elements of its program.
Des diplomates nord-coréens ont annoncé samedi que leur pays allait reprendre les négociations internationales concernant le programme nucléaire de la Corée du Nord. Cette information, confirmée par un responsable américain et officialisée en Corée même par l'agence de presse nationale ''KCNA'' a été largement reprise par les agences de presse internationales (''Reuters'', ''Associated Press'', ''AFP'' etc.).
Corée du Nord consent à reprendre les négociations sur son programme nucléaire
L'accord aurait été trouvé lors d'un dîner entre un négociateur et ancien ambassadeur américain, Christopher Hill et le vice-ministre des affaires étrangères nord-coréen, Kim Gye Gwan. Lors de cette rencontre, M.Gwan aurait même fixé la  comme date pour la reprise des discussions ''des six nations'' (Corée du Nord, Corée du Sud, Chine, Russie, États-Unis et Japon). Les diplomates américains rapportent même que Kim Gye Gwan aurait fixé comme but de ces discussions  .

Cette acceptation de Pyongyang de céder aux pressions venues de toutes parts, intervient alors que Condoleeza Rice, secréataire d'État aux affaires étrangères américaines entame dimanche un long voyage en Asie et particulièrement en Chine. La Chine quant à elle se félicite de cette décision et souligne le rôle qu'elle a joué, alors que les experts considèrent que c'est un communiqué américain affirmant reconnaître la Corée du Nord comme état souverain et assurant une politique non hostile au régime de Pyongyang  qui aurait poussé le gouvernement nord-coréen et en particulier M.Kim, son leader, à accepter les négociations.

La Corée du Nord avait quitté cette même table de discussion de Pékin en février 2004 en affirmant posséder des armes non traditionnelles et plus particulièrement nucléaires. La grande inconnue de cette 4 ronde de négociations sur le sujet est son efficacité, très limitée lors des trois dernières rencontres.