BIR AYAD, Libya — In a defiant speech broadcast to an unusually large gathering of his supporters on Friday, Col. Muammar el-Qaddafi threatened attacks on Europe if NATO did not halt its bombing campaign, even as he also seemed to leave open a door to negotiations.

In the speech, delivered by telephone to thousands of people marching in Green Square in Tripoli, Colonel Qaddafi warned that Libyans would be able to take the battle “to Europe, to target your homes, offices, families, which have become legitimate military targets, like you have targeted our homes,” The Associated Press reported.

He also said he would welcome negotiations if Europe and the United States were willing, but he said if they were not, “we’ll finish the battle.”

With NATO warplanes bombing his strongholds, Colonel Qaddafi now rarely appears in public and favors recorded messages or taped video, for instance, of a meeting he attended in May. Instead, he has been communicating with Libyans and the outside world through recorded messages from undisclosed locations.