Washington -

Outgoing health and human services secretary Kathleen Sebelius says the Obama administration's own predictions that the new health-care law's online sign-up system would be ready by October 1 were “just flat out wrong”.

Sebelius told NBC's Meet The Press in an interview airing on Sunday that the health-care website's launch was “terribly flawed and terribly difficult”.

She says that eight-week period was the low point of her tenure.

Sebelius last week announced her resignation.

She says she wanted to give President Barack Obama enough time to bring in a new health chief.

Sebelius' resignation comes just a week after sign-ups for insurance coverage ended, enrolling 7.1 million people and exceeding initial expectations.

Enrollment has since increased to 7.5 million as people were given extra time to complete their applications. - Sapa-AP