Cuba says US sanctions blocking efforts to open economy to private investment

The United States has demanded that Cuba open up to private investment, and Cuba has passed sweeping reforms to encourage just that. So Cuba's U.N. ambassador says he wants to know why Washington keeps piling on sanctions that stymie the very economic opening it has sought for decades. Ambassador Ernesto Soberón Guzmán, in an interview this week with The Associated Press, directed his question to…