Switzerland has pulled out of a United States Senate hearing on tax issues in protest at a civil lawsuit against the country's biggest bank, UBS.
The government had intended to send a representative to the Permanent Subcommittee on Investigations hearing on Tuesday, part of a probe into alleged tax evasion by UBS clients in the US.
The hearing will focus on the Internal Revenue Service's request to UBS to provide more information about US citizens' accounts.
"The Swiss government regrets that the US Justice Department has threatened UBS with unilateral measures, despite the collaboration of the bank and the Swiss authorities with the American authorities," finance ministry spokesman Roland Meier said on Sunday, quoting from a letter informing the Senate of the Swiss government's decision to cancel its attendance.
He noted however that the letter also stated that Switzerland remained ready to collaborate "in accordance with legal arrangements and bilateral accords in place".
After months of pressure, UBS and Finma announced on Thursday the decision to hand over confidential details of 250 clients whom the US authorities suspect of tax evasion.
But on the same day US tax collectors issued UBS with a civil lawsuit seeking the identities of about 52,000 US clients who allegedly kept billions of dollars at the bank to dodge the Internal Revenue Service. UBS has said it will fight the case.