These are not reported on your tax return as taxable income but there may be an FBAR reporting regulation if the value of the pension is more than $10,000 at any time during the tax year. Also there may be a 8938 filing requirement if the amount of the pension is is more than $100,000 on the last day of the tax year or more than $150,000 at any time during the tax year for a MFJ taxpayer.
8938 IRS Instructions
FBAR filing