Senators have questioned whether the deal could violate U.S. sanctions – designed to punish Moscow for aggression in Ukraine – if Rosneft ever collected the collateral. It has also drawn objections from foreign companies seeking compensation for nationalizations by the socialist government of Venezuela under the late Hugo Chavez. Canadian miner Crystallex, for instance, has objected to the use of Citgo as collateral for Rosneft's loan, charging that Venezuela is seeking to reduce its exposure to assets in the United States to prevent Crystallex from ever collecting on its award, issued by a World Bank arbitration panel.