Collecting a Debt internationally

About four years ago a person i used to call a friend borrowed some money, This happened on my Stay in The Dominican Republic where the Dominican Peso (DOP) is used. The friend and I signed a payment agreement in that country i have some of his ID information from Dominican Republic.a few months later and no payments being made to our agreement i investigated and could not locate such friend i was told this person had obtained a U.S Visa and is now residing in the U.S, i have not been successful in obtaining info about his location, what can i do to make it known in the U.S this person has a debt with me, can this be brought to justice in the U.S since it was performed at an international location. P.S i am a U.S resident as well.
thanks in advanced.

Yes it can but you have to collect on the debt where the person is residing or where he has assets.

So it may be best to act where he is located.

ok thanks can you please guide me or give me some tips as to how would i go about or what would be the most efficient method of locating this person and if i get his location where would i head to in order to file the report. thanks!