If you're thinking that just because you're a student ambassador representing the US you have to wear a suit and tie, you are SO wrong. Here are a few requirements below that our group went by. These could change depending on who your leader is.
When you are meeting with an official or going to a special dinner or concert, you have to dress formally. For guys this is just a shirt and tie and for girls, it's a dress, skirt, or nice pair of slacks.
Most days--just be tasteful. Jeans, shorts, and a clean shirt will be fine for many days of the trip. If you really want to wear your PtoP shirt, you can. Our group only HAD to wear it about 5 times throughout the trip.
Around the beach, hotels, and freetime, you can basically wear whatever you want, but again, be tasteful. Don't leave a bad impression with the locals. Jeans, running shorts, t-shirts, and swim suits are some examples.
*There shouldn't be any of the following:
2)Clothing with rude expressions or containing logos promoting illegal or inappropriate behavior
3)Tops that bare midriffs
4)Excessively short shorts or skirts.
**Prior to the trip, you will be mailed a detailed packing list which will help even more in preparing for your adventure.