Havana (AFP) - Cuba rallied behind Venezuela on Tuesday, offering its closest ally "unconditional support" after US President Barack Obama authorized new sanctions against officials of the turbulent South American oil producer. The Cuban reaction marked its first public confrontation with the United States since the two countries began discussions in December on fully restoring diplomatic relations. Cuba joins other leftist regional governments in closing ranks with Caracas in the deepening US-Venezuela row. An official statement published in the island's state-run media called Obama's executive order implementing the sanctions "arbitrary and aggressive." "Cuba again reiterates its unconditional support and that...