According to Senator Smith, how will the trade restrictions against Vietnam end?

A senator is urging President Clinton not to end the trade restriction against Vietnam. Republican Senator Bob Smith says the restrictions should continue until Vietnam provides more information about Americans missing from the Vietnam War. President Clinton must decide by next week if he will order the restrictions continued for another year. On Tuesday, the Defense Department released some documents from the former Soviet Union that appeared to show that North Vietnam held hundreds more of American war prisoners than it had admitted. Defense officials say the documents must be examined closely.