WASHINGTON — Chelsea Manning, the former Army intelligence analyst convicted in 2013 of leaking archives of secret military and diplomatic documents to WikiLeaks, revealed in an interview that she had been subpoenaed to testify before a grand jury — and vowed to fight it.

The subpoena does not say what prosecutors intend to ask her about. But it was issued in the Eastern District of Virginia and comes after prosecutors inadvertently disclosed in November that Julian Assange, the founder of WikiLeaks, has been charged under seal in that district.

Ms. Manning, who provided a copy of the subpoena to The New York Times, said that her legal team would file a motion on Friday to quash it, arguing that it would violate her constitutional rights to force her to appear. She declined to say whether she would cooperate if that failed.

“Given what is going on, I am opposing this,” she said. “I want to be very forthright I have been subpoenaed. I don’t know the parameters of the subpoena apart from that I am expected to appear. I don’t know what I’m going to be asked.”