Last week, President Barack Obama gathered some of his top advisers in the Oval Office to discuss the problem-plagued rollout of his health care legislation. He told his team the administration had to own up to the fact that there were no excuses for not having the health care website ready to operate on Day One.

The admonition from a frustrated president came amid the embarrassing start to sign-ups for the health care insurance exchanges. The president is expected to address the cascade of computer problems Monday during an event at the White House.

Administration officials say more than 476,000 health insurance applications have been filed through federal and state exchanges. The figures mark the most detailed measure yet of the problem-plagued rollout of the insurance market place.

However, the officials continue to refuse to say how many people have actually enrolled in the insurance markets. And without enrollment figures, it’s unclear whether the program is on track to reach the 7 million people projected by the Congressional Budget Office to gain coverage during the six-month sign-up period.

The first three weeks of sign-ups have been marred by a cascade of computer problems, which the administration says it is working around the clock to correct. The rough rollout has been a black eye for Obama, who invested significant time and political capital in getting the law passed during his first term.

The officials said technology experts from inside and outside the government are being brought in to work on the glitches, though they did not say how many workers were being added.

Officials did say staffing has been increased at call centers by about 50 percent. As problems persist on the federally run website, the administration is encouraging more people to sign up for insurance over the phone.

The officials would not discuss the health insurance rollout by name and were granted anonymity.

Despite the widespread problems, the White House has yet to fully explain what went wrong with the online system consumers were supposed to use to sign up for coverage.

Administration officials initially blamed a high volume of interest from ordinary Americans for the frozen screens that many people encountered. Since then, they have also acknowledged problems with software and some elements of the system’s design.

Interest in the insurance markets appears to continue to be high. Officials said about 19 million people have visited HealthCare.gov as of Friday night.

Of the 476,000 applications that have been started, just over half have been from the 36 states where the federal government is taking the lead in running the markets. The rest of the applications have come from the 14 states running their own markets, along with Washington, D.C.

Americans seeking health coverage through the Affordable Care Act must fill out applications before selecting a specific plan. The forms require personal information, including income figures that are used to calculate any subsidies the applicant may qualify for. More than one person can be included on an application.

The White House says it plans to release the first enrollment totals from both the federal and state-run markets in mid-November.

An internal memo obtained by The Associated Press showed that the administration projected nearly a half million people would enroll for the insurance markets during the first month.

Officials say they expect enrollments to be heavier toward the end of the six-month sign up window.

Problems with the rollout were largely overshadowed by Republican efforts to force changes to the health care law in exchange for funding the government. That effort failed and the government reopened last week with “Obamacare” intact.

Some Republicans are now calling for the resignation of Health and Human Services Secretary Kathleen Sebelius. The White House says it has complete confidence in her. House Republicans have scheduled a hearing next week to look into the rollout problems.

White House allies say they’re confident the problems are being addressed.

“There’s no question the marketplace website needs some improvement,” said Sen. Max Baucus, D-Mont., one of the architects of the law. “The administration needs to fix the computer bugs and I’m confident that they’re working around the clock to fix the problems.”

(AP)