BBC News with Neil Nunes. The United States and the European Union have agreed to the toughest sanctions yet against Russia over its support for rebels in Ukraine. President Obama said existing sanctions had already weakened Russia's economy and the new measures would weaken it further. His announcement came hours after the EU announced similar sanctions. "We're blocking the exports of specific goods and technologies to the Russian energy sector, we're expanding our sanctions to more Russian banks and defense companies, and we're formally suspending credit that encourages exports to Russia and financing for economic development projects in Russia. ____________________________________ 尼尔?努内斯为您报道BBC新闻.美国和欧盟因俄罗斯对乌克兰叛军提供帮助一致决定对其采取最严厉的制裁.奥巴马总统表示现有制裁措施已经削弱了俄罗斯的经济,即将实施的新措施力度将更加强大.这一声明是在欧盟发表完类似声明数小时后发出的. "我们封锁俄罗斯特定商品的出口,阻止其能源部门引进先进技术,我们将制裁范围扩展到俄罗斯的银行和国防企业.我们正式终止对俄罗斯贷款,这些贷款会用于 鼓励向俄罗斯出口并对其经济发展项目提供资金支持._________________________