Do undergraduate degree from good school in Nepal/India and come to USA for graduate degree. 

 What truenepalidude said. 

I totally agree with truenepalidude.
Do not send your little brother to study for his undergraduate degree in US if your family cannot support him financially. With little research, you can know that an international student in US is legally allowed to work for only 20 hours/week  and that too is only on-campus job. In summer and winter holidays (roughly around four months), he can work for 40 hours/week.
This earning will barely be enough for his living cost and little or no money will be left for his tuition fees. Then he'll be compelled to work illegally and overtime which can affect his studies. His physical as well as mental health can be affected as well due to huge pressure of financial worries in addition to worries related to studies and and maintenance of legal status.
I strongly advise parents and guardians in Nepal not to send their teenage kids for undergraduate degrees in US, unless they get 100% scholarship which is again very unlikely. Instead, please let them get undergrad degree in Nepal/India with good GPA score. Then they can come for graduate degree to US. In most of the cases, Universities provide financial assistanceship in grad programs.

doing undergraduate from recognized 4 year college like KU or colleges from India and coming to the US for the graudate program is a better idea.

It is way much better to first become a permanent resident if you already have undergrad degree and then go to school with govenment grants.

what is the field of interest of your 'little brother' ? If it is engineering or computer science, I don't want your 'little brother' come here work 60 hrs and finish his Bachelor's. If you can not support from there don't send him abroad, 'please'. In my opinion, the only benefit of going overseas for higher studies for Bachelor's degree is 'ease of learning new language' due to age.

I will say the same thing "finish Undergraduate in Nepal " and then try after that otherwise it will be hard for him ,this is my suggestion as a Nepali brother.

The first thing that is important to understand is to give away the thought that "one can work and support study".Working and study only ruins your youth-you end up with poor academics and always broke, specially true for undergrads. The best option on the table is to explore his chances for scholarships. As soon as you get  rid of financial burden-everything becomesmuch  easier and you have better time for studies. So see if he can get that scholarships or else like many suggested up there, make him get his  bachelors (4 years, NOT 3 years,it  will be another trouble)  degree in Nepal with excellent and come to the States for Masters. Meanwhile DV pani vardai garnu- u never know ;p.