The United States announced steps Wednesday toward an elusive tax deal with Switzerland, as well as another with economic partner Japan.

The US Treasury Department said it would discuss how Swiss and Japanese firms can navigate a 2010 US tax law that has been controversial in many countries because it requires banks to reveal information about their clients.

In particular, Switzerland and the United States have butted heads over the rules.

Washington accuses Swiss banks of harbouring tax dodgers and has threatened fines for their failure to be upfront about clients' holdings.

But the banks insist they have a duty under Swiss or other nations' laws to defend client privacy.

The Treasury Department said the agreement to work on the 2010 law's implementation would "strengthen and improve" cooperation and help firms balance competing legal requirements.