3月31日至4月1日,第四届核安全峰会在美国首都华盛顿举行。国家主席习近平与会并作主旨发言。他就如何加强国际核安全体系建设提出“应强化政治投入、强化国家责任、强化国际合作、强化核安 From March 31 to April 1, the Fourth Nuclear Security Summit will be held in the capital of the United States in Washington. President Xi Jinping attended the meeting and made keynote speeches. He proposed on how to strengthen the construction of an international nuclear safety system that ”political investment should be intensified, national responsibilities strengthened, international cooperation strengthened and nuclear security strengthened