I am inviting my parents over the States and I want to return date to be as flexible as it can be. Therefore, I wanted to purchase just one way ticket (KTM - US) for now. I referred a lawyer and he said one way ticket for B2 visa should be fine. However, I also heard that there could be problem at departure in KTM for B2 visas to have one way ticket. Does the KTM airport go through all that details and can also restrict travel? Does anyone know about this situation? Also, do the port of entry officer at arrival go through the return ticket and verify that? I would appreciate any information on regards to this.

Thanks,