You want to move out from Russia or just want to work in US?
I don’t think that dealing with a one or two agencies will do any good for you. They play by the job specs and most of the times ( I can say that from my previous job hunting experience) those jobs specs are being received by a quite a big number of head hunters.
I would recommend you to do the following: try to get a job first in US company having offices in Moscow or St.Pete and apply there. Once get a job there it would be easier for you to make the next move.
Keep sending your resumes.
Additionally post your resume on Dice.
I know that in the past such countries as Canada, some of EU countries, NZ welcomed IT specialists. If it is still true, maybe you can apply there.