Why do we not have a free trade agreement with Colombia? Yet we continue to trade with countries like China?

I understand that we trade with China because they buy our debts which allows us to continue buying Chinese exports, but what about countries like Colombia? Who are actually our allies? The old excuse has always been because of the labor practices and mistreatment of unions in Colombia..but is there a political agenda or something else that is stopping us from having free trade with Colombia??