It's very difficult. I would start with angels -- I think traditional VCs will not do it at all due to financial regulations and lack of physical presence.
Try AngelList. Try for 500s or other groups which specifically like to invest outside of America.
It is possible but difficult.
There are some structural issues that are unrelated to your company. Many venture funds have limited partnership agreements that restrict the geographies of their investment. You'll often see that many venture firms create geographic specific funds, ala, Sequoia which has funds in the US, Israel and China see http://techcrunch.com/2012/12/17/sequoia-raises-700m-for-global-growth-fund/ for more details. It does depends on the specifics of the specific fund. There are funds like 500startups that have been looking specifically at Latin America and South America as regions of growth for investment.
Looking towards individual angel investors maybe easier. Using tools like AngelList http://angel.co/ access to both accredited and non-accredited investors that can help you raise funding.
I'm actually from Colombia and was able to raise capital in Silicon Valley for my startup three months after I moved to San Francisco.
My idea was originally conceived in Medellin, Colombia but I figured a way to build the prototype and then establish our headquarters in Silicon Valley.
Here is a previous answer that details a little bit of the process of how I went about investors
More than happy to tell you the story and process of how we did on a brief call :)