From Washington, this is VOA news. I'm Dave DeForestreporting.______________________Before the opening, Mr. Obama met with South Korean President Park Geun-hye and JapanesePrime Minister Shinzo Abe at a White House to discuss North Korea's nuclear and missile tests.President Obama:"We are united in our efforts to deter and defend against North Korean provocations. Werecognize that our security is linked; that we have to work together to meet this challenge." 来自华盛顿,这里是VOA新闻.我是大卫`迪福斯特报道.____________会议召开前,奥巴马在白宫会见了韩国总统朴槿惠与日本首相安倍晋三,共同讨论了朝鲜核试验与导弹测试问题.奥巴马说:"我们应该努力团结起来阻止和抵抗来自朝鲜的挑衅.我们意识到大家的安全是联系在一起的:我们要齐心协力共同应对这一挑战."