It could have been both of the ones above I will never know as they tore the place down but I do know it wasn't a ordinary vine like MG or something like that just big white trumpet shaped flowers and fragrant. I was only there for a minute but it sure was interesting!! Thanks for everybody's input.. Caarol Z5N

A huge mature vine like this is going to put up a heckuva fight, no doubt. Bittersweet is a notoriously hard-to-kill entity. I don't own any kind of chemicals, but short of bulldozing this whole area and removing the top layer of soil (the good part - a very undesirable idea,) it would be about a full-time job trying to get rid of something like that with only manual efforts, and if faced with the same situation, I would buy something. But it's a common fallacy that a ton of 'cide will be more deadly than applying according to label directions. Since you're willing and able to perform a lot of manual mutilation and removal (which will seriously impede this plants' ability to continue growing,) you should be able to keep the amount of 'cide used to a tiny amount, applied directly and carefully to cut ends, using a product made for this purpose. Something like roundup that affects by being "ingested by leaves" is not what you need for that because you would have to spray a huge amount of product just to apply it according to label directions. Regardless of what's in your neighbor's yard, you probably don't want to dump a bunch of toxins on your own property. When the leaves are all gone later, you can keep working on it if you are so inclined, especially since you intend to remove it all, alive or dead, anyway. The less live vine mass there is, the less stored energy reserves there are to grow back. Unfortunately, you won't know until spring how much is still alive and growing back again. It looks like this vine has spread and may have roots all throughout the area, as mentioned above, and likely seeds have produced individual sprouts as well, which would mean that it's actually a patch of autonomous plants, which will each have to be killed. Concentrate on getting the spot cleared for your tree, and keep attacking the other still-alive parts of the vine in the same way, cutting and pulling what you can, 'cide-ing stumps. Can you pull some of it out with a truck?

Greenbriar? (a.k.a. smilax)

More info needed. What tropical climate? Please tell us that you didn't hide it in your luggage to sneak it over the border, lol.