One of the major purposes of the World Trade Organization is to encourage free trade among countries. Explanation:

The World Trade Organization is the only international organization that deals with global standards that regulate trade. Its main function is to ensure that commercial flows circulate as smoothly, predictably and freely as possible.

Also it can :

Make Trade negotiations.
Stimulate economic growth and employment.
Dispute settlement.
Ensure application and monitoring.
Contribute to peace and stability