I have recently been alerted to this opportunity by Budd Hall: The Trans-Atlantic Platform for Social Sciences and the Humanities appears to me to be a welcome development. In summary as the website says:

Major research funders in Europe and the Americas have partnered to pave the way for increased transatlantic research collaboration in the social sciences and humanities. This includes strengthening the pillars that support research cooperation and building new pillars to meet the needs of 21st century research. It includes broadening the bridges that connect research and removing the barriers that block transatlantic research projects from taking place.

Calls for proposals have as yet been limited with only one significant opportunity so far having emerged with researchers from the State of São Paulo (Brazil), the United Kingdom and the Netherlands having been invited to apply for funding for joint research projects in the field of Sustainable Urban Development.

However I suggest that you watch this space.