Sen. Robert Byrd renewed his invitation to Homeland Security Director Tom Ridge on Wednesday to testify before a congressional committee about spending on homeland defense.

The White House, however, again described Ridge as a presidential adviser and said it would be more appropriate for other government officials to appear before Byrd's committee.

Byrd, chairman of the Senate Appropriations Committee, has repeatedly requested that Ridge testify about President Bush's request for $38 billion for domestic security programs.

Ridge has briefed members of Congress behind closed doors but has refused to testify at open hearings. The White House argues that Ridge has no operational or budgetary authority and as an adviser to Bush, cannot be compelled to testify, as can Cabinet secretaries and other top administration officials.

In renewing the invitation to Ridge, Byrd and the Appropriations Committee's top Republican, Ted Stevens of Alaska, said they would have more homeland defense hearings in next week and in early May and would have other Cabinet secretaries testify.

But "this is no substitute to having the one official testify whom the president has designated as responsible for coordinating the executive branch's effort to detect, prepare for, prevent, protect against, respond to and recover from terrorist attacks in our nation's homeland," Byrd and said in a letter to Ridge.

It seemed unlikely that the White House would accept this offer, either.

"Governor Ridge is an adviser to the president," Ridge spokesman Gordon Johndroe said. "It is more appropriate for the Cabinet secretaries that the senators have said they invited to testify to testify because they have operational and budgetary authority."