If you don't pay loans, they can come after you to a certain extent. They can sue you and can even take money out of pay check etc. Nobody is going to do that for 3000 dollars. Your credit score will go down. You will not be able to get more loans because of that. But, it DOES NOT effect your immigration matters. Unless you are just not paying it while still having a lot of money, treat this like a business matter without a lot of emotiOns attached to it.
On the other hand, like others have said, if this with a major bank and credit cards etc. You can work out a lOng term payment plan and I think they may even cut some of the balances.