Most job sites are regional in nature, so it would be a good idea to narrow down your criteria by cluing us into which part of the planet you are looking for work in. When all else fails, click here.
Since you are asking about two different countries, I'm going to guess you aren't a citizen of either. You should probably start by researching how to obtain a work visa (in the US, H1B).
I'm a US citizen so I've never jumped through those hoops. There's plenty of adventurous types in this forum. Maybe they'll chime in. While you're waiting, search this forum and you'll find plenty of information.