I spent a month studying AGI on a hobby level and the answer, from what I can tell, is that it isn't possible right now because we can't even model how human level intelligence works. There are also several ways to approach developing AGI and we don't even really have a good idea on which approach is best. I am not convinced current human level intelligence is enough to ever figure out this model, but I believe future genetically modified humans may have a much better chance.