Pillar 3a retirement savings account

Hi,

I am a Swiss-American citizen living and working in Switzerland where it is common - and desirable - to have a pillar 3a retirement acount for old age savings in addition to social security and pension plans at work. I am running into the problem that no Swiss bank would accept me as a pillar 3a account holder because "US persons" cause the banks additional paper work and reporting requirements to US tax authorities. Is anyone aware of ways to have a pillar 3a account in Switzerland? Perhaps with a US bank in Switzerland? Thank you for any advice.

Gregor Schmid