Unfortunately, contributions to Pillar 2 and Pillar 3 plans cannot be deducted and must be reported as income on a U.S. tax return.
Some good news: because contributions to Pillar 2 and 3 plans are taxed, you won’t pay taxes later on when you withdraw money from these funds. Typically, once withdrawn, this money would be considered passive income and would not be included in the Foreign Earned Income Exclusion, so that you would owe tax on withdrawals. However, because the contributions are taxed when made, you will only owe tax on growth, and Switzerland’s Foreign Tax Credit will offset this tax.
In this way, double taxation is avoided, and you won’t have to worry about being taxed later because you're paying taxes on your plan now.