“这是一个巨大的成就。”

以上是4月1日奥巴马总统在第4届核安全峰会（Nuclear Security Summit）闭幕式上发表讲话时所说的。他还指出，“恐怖主义分子……为制造核装置到处寻求致命的原材料，但现在全世界广大地区都已成为防范核恐怖主义的阵地 。”

奥巴马总统与全世界各地50多位领导人出席了这次核安全峰会。这次会议审议了保障核材料安全和销毁核材料的进展，同时讨论促进不扩散的共同目标及打击核走私的途径。

自2010年第一届核安全峰会召开以来，全球约有3.8吨高浓缩铀和金属钚的安全得到保障，这些材料足以制造150件核武器。奥巴马总统表示，“这些材料永远不可能落入恐怖主义分子之手。”

奥巴马总统指出，南美（South America）现在已经完全消除了危险的材料。中欧（Central Europe）和东南亚（southeast Asia）将在今年晚些时候实现消除核材料的目标。

奥巴马总统强调，为了降低核恐怖主义的威胁，还有更多的工作需要做。

他说，“实现我们的目标不可能一蹴而就，或许不可能在我有生之年完成。但是我们已经开始努力。今天我赞同维持一个强大的机制……承担这项工作，提供继续这项使命所必需的资源和技术支援。” 

Obama: We’re making the world off-limits to nuclear terrorists

“A remarkable achievement.”

That’s what President Obama said April 1 at the conclusion of the fourth Nuclear Security Summit. “As terrorists … look around for deadly ingredients for a nuclear device, vast regions of the world are now off-limits.”

Obama and more than 50 world leaders met in Washington to review progress in securing and eliminating nuclear materials. They discussed ways to advance shared nonproliferation goals and combat nuclear trafficking.

Since the first such summit in 2010, about 3.8 tons of highly enriched uranium and plutonium — enough to produce some 150 nuclear weapons — have been secured. “That’s material that will never fall into the hands of terrorists,” Obama said.

He noted that South America is now completely free of these dangerous materials. Central Europe and Southeast Asia will be free of them later this year, he added.

Still, the president acknowledged that more remains to be done to reduce the threat of nuclear terrorism.

“Realizing our vision will not happen quickly, and it perhaps will not happen in my lifetime. But we’ve begun,” he said. “Today we agreed to maintain a strong architecture … to carry on this work and to provide the resources and technical support that is needed to continue this mission.”