WASHINGTON — Pentagon officials disclosed Wednesday that American warplanes had continued to strike targets in Libya even after the Obama administration said the United States was stepping back from offensive missions and letting NATO take the lead.

Although American officials had said that no aircraft would fly offensive strike missions, unless officially approved in Washington, 11 warplanes have flown 97 sorties intended to electronically jam or otherwise suppress Libyan air defenses since April 4, when command of the mission was handed over to NATO and the United States publicly said it was stepping back to a supporting role.

The number of actual missile strikes during those missions was only three; all were against Libyan air defense systems, whether radars, command-and-control sites or surface-to-air missiles. Two of them were to destroy hard-to-find and hard-to-strike mobile targets.

In explaining the gap between public statements and operational details, officials said the trio of strikes on Libyan targets since April 4 were classified as defensive, not offensive.