WASHINGTON -- The White House is hampering a Senate inquiry into the government's response to Hurricane Katrina by barring administration officials from answering questions and by not handing over documents, senators leading the probe said yesterday.
In some cases, staff members at the White House and other federal agencies have declined to be interviewed by congressional investigators, said the top Republican, Susan M. Collins of Maine, and the ranking Democrat, Joseph I. Lieberman of Connecticut.
Both serve on the Senate Homeland Security and Governmental Affairs Committee.
In addition, agency officials have not answered seemingly innocuous questions about times and dates of meetings and telephone calls with the White House, the senators said.
A White House spokesman, Trent Duffy, said the administration is committed to working with the separate Senate and House investigations of the Katrina response but wants to protect the confidentiality of presidential advisers.
''No one believes that the government responded adequately," Lieberman said. ''And we can't put that story together if people feel they're under a gag order from the White House."
Collins, the committee's Republican chairwoman, said she respects the White House's reluctance to disclose advice to President Bush from his top aides, which is generally covered by executive privilege.
Still, she criticized the dearth of information from agency officials about contacts with the White House.
''We are entitled to know if someone from the Department of Homeland Security calls someone at the White House during this whole crisis period," Collins said. ''So I think the White House has gone too far in restricting basic information about who called whom on what day."
She also said that it ''is completely inappropriate" for the White House to bar agency officials from talking to the Senate committee.
Duffy, the White House spokesman, said the administration's deputy homeland security adviser, Ken Rapuano, has briefed House and Senate lawmakers on the federal response. A ''lessons learned" report from a Homeland Security adviser, Frances Fragos Townsend, also is expected in coming weeks, Duffy said.
But he defended the administration's decision to prohibit White House staff members or other presidential advisers from testifying before Congress.
''There is a deliberate process, and the White House has always said it wants to cooperate with the committee but preserve any president's ability to get advice from advisers on a confidential basis," Duffy said. ''And that's a critical need for any US president, and that is continuing to influence how we cooperate with the committees."
Collins and Lieberman did not directly answer questions about whether they plan to subpoena the White House to get the information they seek, though Collins said she does not believe subpoenaing the Homeland Security Department is necessary.
The Senate inquiry is scheduled to conclude in March with a report detailing steps the government took, and did not take, to prepare for the Aug. 29 storm.
Investigators have interviewed about 260 witnesses from federal, state, and local governments and the private sector. The committee has received an estimated 500,000 documents.
Lieberman said the Justice and Health and Human Services departments ''have essentially ignored our document requests for months," while the Department of Health and Human Services has not allowed interviews of its staff. He said the Homeland Security response was ''too little, too late."