Wall Street Journal reported Wednesday top Chinese nuclear experts have expanded their estimate of North Korea's nuclear capability beyond previous U.S. estimates, making Pyongyang's arsenal a potential regional security threat. VOA\'S Victor Beattie reports. The Wall Street journal says the Chinese estimate that the North may already possess 20 nuclear warheads was relayed during a closed-door meeting with U.S. nuclear specialists at the China Institute of International Studies in February.__________________________________________________ 《华尔街日报》周三报道称,中国顶级核专家加大了对朝鲜核能力的估计,高于此前美国的预估。此举使得平壤军火库成为区域性的潜在威胁。美国之音维克多贝蒂报道。《华尔街日报》