The Bush administration has thrown its support behind a House bill to be voted on Thursday that will completely overhaul the troubled Immigration and Naturalization Service.

Attorney General John Ashcroft appeared on Capitol Hill Thursday to endorse the Barbara Jordan Immigration Reform and Accountability Act, which will restructure it into two organizations, one for enforcement of immigration rules and one for administration of visa requests.

"It is time to separate fully our service to legal immigrants who help build America... from our enforcement against illegal aliens who violate the laws of America," Ashcroft said.

The bill is expected to pass with overwhelming support. The bill passed the House Judiciary Committee earlier this month by a 32-2 vote.

Up until now, the White House had resisted new legislation, preferring to make internal changes to the agency and consolidating the INS and the Customs Service into one unit under the Justice Department.

The Administration's change of heart about the INS reforms may have been prompted in part by what was described as an embarrassment to President Bush when a Florida flight school received paper notification in February that two of the hijackers who crashed their planes into the World Trade Center had their student visas approved. A month later, the INS reported that it had allowed four Pakistani merchant marines to disembark their ship in Norfolk, Va., and they never returned.

Thirteen of the 19 terrorists who hijacked four commercial jets on Sept. 11 entered the United States legally on tourist, business or student visas. The government has acknowledged that four of those men allegedly remained in the United States after their visas had expired.

Ashcroft was expected on the Hill Wednesday to endorse the bill, authored by House Judiciary Committee Chairman James Sensenbrenner, R-Wis., but cancelled at the last minute because of what Department of Justice officials described as logistical problems.

The Sensenbrenner bill creates within the Justice Department an "Agency for Immigration Affairs" headed by the associate attorney general for immigration affairs. Within this new agency there will be two bureaus: the Bureau of Immigration Services and Adjudications and the Bureau of Immigration Enforcement. According to the bill, a director with 10 years of experience would head each bureau.

The bill requires the attorney general to establish an Internet-based system that permits people with applications filed with the INS to access online information about the status of the application.

Ashcroft said he would be "delighted" if INS Commissioner James Ziglar spearheaded the changes.

Currently, the INS has a backlog of some five million applications, and estimates that it has lost track of more than 314,000 aliens ordered to be deported but still in the country.

Catherine Herridge is an award-winning Chief Intelligence correspondent for FOX News Channel (FNC) based in Washington, D.C. She covers intelligence, the Justice Department and the Department of Homeland Security. Herridge joined FNC in 1996 as a London-based correspondent.