Washington accuses UBS, Switzerland's largest bank and the world's number one wealth manager, of helping wealthy American clients hide money in secret Swiss bank accounts.
The Swiss bank in February agreed to pay $780 million to avert criminal charges but still faces a request by U.S. tax authorities, the so-called John Doe summons, to disclose the identities of 52,000 bank clients.
The latest developments do not, in any way, weaken UBS' legal position relating to the John Doe summons of the IRS, the bank said in a statement published on its website on Friday.
The latest developments demonstrate that this matter should be resolved through bilateral discussions between governments and not in a courtroom, it said.
Switzerland on March 13 agreed to sign up to international standards for tax cooperation and transparency set up by the Organization for Economic Cooperation and Development.
Berne wants to redraft bilateral tax treaties with major countries to include provision for cooperation on tax evasion and said it would like governments to consider ways to help citizens with undeclared assets in Switzerland to legalize their cash.
UBS said Switzerland's decision did not lead to immediate changes for wealthy clients.
The bank would help clients to decide on where to bank and also assist them with documents so they could fulfill all tax obligations, it said.
(Writing by Lisa Jucca; Editing by David Cowell)