President Barack Obama said Monday there was "no excuse" for the cascade of computer problems that have marred the rollout of key elements in his health care law but declared he was confident the administration would be able to fix the issues.

"There's no sugarcoating it," he said. "The website has been too slow, people have gotten stuck during the application process, and I think it's fair to say that nobody has been more frustrated by that than I am.”

The president said his administration was doing "everything we can possibly do" to get the federally run websites up and running. And he guaranteed that everyone who wants to get insurance through the new health care exchanges would be able to as the six-month enrollment period continues.

Obama made his comments during an event in the White House Rose Garden that had the feeling of a health care pep rally, with guests applauding as he ticked through what the White House sees as the main benefits of the law.

The president was introduced by a woman who had successfully signed up for health insurance through the marketplace in her home state of Delaware, telling the crowd that she was previously denied coverage by three private insurance companies because of existing conditions. She said the new health insurance plan that she signed up for through the Affordable Care Act (ACA) saves her $150 per month on premiums.

Acknowledging that technical problems have been part of the exchanges' rollout, Obama insisted that the health care law was about more than just a website alone.

"The essence of the law, the health insurance that's available to people, is working just fine," he said.

The White House says 20 million people have visited HealthCare.gov since the site went live on Oct. 1. Officials also say half a million people have applied for insurance on the federal- and state-run websites.