It is possible and we have just completed this (although it did take a while)
The easiest way to do this is to open a business bank account in YOUR country with a bank that has a strong presence both in your country AND in the US. In our case we used HSBC.
Once we did this, we contacted their international commercial department and initiated the process.
We did need to have a registered business in the US (which you can do through an agent).
They will send you all the documents, do a visit of your business premises, need to verify your identity and it may take anything from 8 to 40 weeks to complete.
If HSBC has a strong presence in Singapore I would suggest doing this with them as we have been quite happy with their service.