3. An original signed and detailed statement from the owner or operator of a US registered
aircraft substantiating the need for the A&P certificate. The employer must also list the
specific type of maintenance performed, and duration of employment.
This is not necessary, there may be some B/S reciprocity that an FAA administrator acted on but if you come to the USA to test. I can tell you with complete confidence this is not a requirement. If the DME does not feel your English is adequate you may have a foreign only restriction.
Also to add the ATA system is important, if you can document the time and have the experience that covers work performed in all ATA's you should be good!