BRUSSELS (Reuters) - Germany's acting finance minister said on Tuesday that Berlin wanted European banks to reduce risks on their books before governments can complete a banking union by creating an EU-wide bank deposit guarantee scheme.

Peter Altmaier, a close ally of Chancellor Angela Merkel, also said after talks in Brussels that EU finance ministers had agreed to ask the European Commission to analyse the implications of the U.S. tax overhaul.

European Union finance ministers are discussing how to measure the risks EU banks are exposed to and how and when to reduce them, so the EU can complete a banking union that includes an EU-wide bank deposit guarantee scheme.

The discussion is key to getting the euro zone's largest economy, Germany, to agree to set up the European Deposit Insurance Scheme (EDIS), a Europe-wide plan to guarantee all deposits up to 100,000 euros in any euro zone bank.

(Reporting by Peter Maushagen; Writing by Michael Nienaber; Editing by Madeline Chambers)