Secretary of State Colin L. Powell testified July 16 before a federal grand jury in Washington, State Department spokesman Richard Boucher said Sunday, responding to a Newsweek report that Powell was questioned on a leak to the media about the identify of a covert CIA agent.

Powell was "pleased to cooperate with the grand jury," Boucher said, noting that the secretary was not personally the subject of its inquiry.

But Boucher would not confirm Newsweek's assertion that the inquiry was probing Powell about a leak identifying Valerie Plame, wife of former ambassador Joseph C. Wilson IV. Columnist Robert Novak disclosed Plame's name in July 2003 after Wilson publicly said he undertook a mission for the CIA to Niger in 2002 to investigate intelligence indicating that Iraq had tried to buy uranium from Niger. Wilson said he found no evidence to support the allegations and criticized the White House for including a reference to the claim in President Bush's 2003 State of the Union address.

Boucher said Powell had not called or talked to Novak about Wilson's wife.

Newsweek reported the grand jury wanted to question Powell about discussions he had with Bush during a July 2003 trip to Africa. Powell had a report by the State Department's Intelligence and Research office exploring the Niger export claim.

But Boucher declined to disclose any details. "As grand jury matters are secret, any further questions must be referred to the Department of Justice," Boucher said in a statement issued to reporters traveling with Powell in Poland.

-- Robin Wright