Homeland Security Director Tom Ridge will fill in House lawmakers on his domestic-security agenda -- but he won't be testifying formally.

Ridge will be making informal briefings to members of the Republican-run House Government Affairs Committee on April 11, and House Energy and Commerce Committee in the near future, likely this month. Ridge promised last week to give informal briefings to the House and Senate, taking questions from lawmakers in front of the public and news media.

Ridge has met with individual members of Congress and their caucuses, but April 11 will be the first time he addresses a committee, spokesman Gordon Johndroe said.

But Ridge will not testify formally in front of any committee despite a Senate committee request to do exactly that, Johndroe said.

Whether or not the director can be compelled to testify formally is at the center of how the executive and legislative branches are defining the new director's power and accountability.

Senate Appropriations Committee Chairman Robert C. Byrd, D-W.Va., and the committee's ranking Republican, Sen. Ted Stevens of Alaska, have requested that Ridge testify at an April hearing. They want to hear about the administration's request for $38 billion for domestic-security programs.

The "informal briefing" approach will not satisfy Byrd, who continues to seek a formal briefing, Byrd spokesman Tom Gavin said.

No Senate committee has sought an informal briefing from Ridge, Johndroe said.

The administration contends Ridge is a presidential adviser without budgetary or operational authority, and so cannot be compelled to testify, as Cabinet secretaries and other top government officials can.

It was not clear Wednesday how Ridge's briefing will differ from formal testimony.

Testimony generally is given in a public hearing, with members of the public and news media present, Gavin said.

Ridge is open to having the April 11 session open to the public and press, but will defer to the committee, he said. Johndroe referred questions to the Government Affairs Committee.

Messages left with the Government Affairs Committee were not immediately returned.

A spokesman for the Energy and Commerce Committee said it will defer to Ridge. A decision on whether to open the session will hinge on whether Ridge believes he can speak candidly about security and other issues, said Ken Johnson, spokesman for Rep. Billy Tauzin, R-La., the committee chairman.

"We're willing to meet with Governor Ridge anytime, anyplace, behind closed doors or in an open forum. It's his call," Johnson said.

The Associated Press contributed to this report.