Health and Human Services Secretary Kathleen Sebelius said the tech team fixing the much-maligned had dramatically improved the website, urging the public not to stop trying to sign up for Obamacare.

In a new op-ed for USA Today, President Obama's health chief insisted that the administration had met its Dec. 1 goal for the online marketplaces to work for the "vast majority" of users.

“Today's user experience on is a dramatic improvement over where it was on Oct. 1. The site is running faster, it's responding quicker and it can handle larger amounts of traffic,” she wrote.

However, insurance companies say that many of the so-called “back-end” issues with Obamacare have yet to be fixed. Insurers complain they are still not receiving the correct information for many enrollees in the new health program, casting doubt on whether consumers will successfully receive coverage for 2014.

And Republicans argue that the problem-ridden website is just the tip of the iceberg for Obamacare woes. GOP leaders have shifted away from hammering the website to focusing on the policy implications of the president’s signature domestic achievement — Republicans insist it will lead to “rateshock” and consumers losing their preferred doctors.

Sebelius acknowledged that problems would persist on the federal website, even though administration officials believe it can now handle 50,000 simultaneous users.

The White House has urged allies not to heavily promote the website because of fears that it would crash under a glut of traffic.

Cognizant of future technical issues, Sebelius said that Americans seeking insurance coverage have options at their disposal beyond

“There are many ways to sign up for coverage: online, by phone, in person and by mail,” she wrote. “In many cases, you can also directly enroll through an insurance company.”

And Sebelius also issued a plea that has become all-too-common for the Obama administration during a rough political stretch.

“To those Americans who have experienced difficulties online: Please do not give up," she added. "There is help available.”