US President Donald Trump said on Tuesday his trip to the Middle East was "already paying off" as regional leaders followed through on their promise to take a hard line on funding militant groups."So good to see the Saudi Arabia visit with the King and 50 countries already paying off. They said they would take a hard line on funding extremism, and all reference was pointing to Qatar. Perhaps this will be the beginning of the end to the horror of terrorism!" Trump said in a series of Twitter posts.