Lawyers told a New York federal magistrate judge that Apple is opposing relinquishing information on at least 15 devices in court cases in California, Illinois, Massachusetts and New York.
A February 17 Apple court document was unsealed today.
In a court filing, the government says Apple's position has been inconsistent.
Apple attorney Marc Zwillinger said the government has asked it to perform "burdensome and involved engineering" to circumvent security.
The company's highest-profile fight has been over information on the phone of a San Bernardino attacker.