The bank said the restrictions have been imposed while it conducts a review of its international wealth management operations and would apply to all foreign client managers.
According to Reuters, the Swiss newspaper Sonntags Blick said over 1,000 employees will be affected by the ban.
UBS has denied introducing the measure to ensure that senior staff are not detained by US authorities investigating the tax fraud allegations, the BBC reports.
The bank is accused of helping thousands of American clients hide their assets from the Internal Revenue Service (IRS).
It had previously supplied US authorities with the names of 300 clients it had advised but subsequently refused to comply with a 'John Doe' order from the IRS demanding the details of 52,000 other customers.
In February, the bank vowed to "vigorously contest" a civil case brought by the IRS seeking judicial enforcement of the order.