The White House announced on Tuesday that about 11.4 million Americans have enrolled in private health insurance through Obamacare during its open enrollment period.

President Barack Obama praised his signature health care law for surpassing his administrations' expectations and providing millions of Americans with the health coverage.

"The Affordable Care Act, aka Obamacare, is working. It's working better than we anticipated, certainly working a lot better than many of the critics talked about early on," said the president in a White House video released on Tuesday.

The open enrollment period to sign up for Obamacare in 2015 began on Nov. 15 and closed on Sunday.

According to the White House, there was a surge of applications in the last nine days of enrollment, especially on Sunday.

"Sunday, February 15 was the biggest enrollment day ever: more new consumers signed up for health coverage than on any day this open enrollment period or the last," the White House said in a statement, reports Reuters.

Although the enrollment window officially closed on Feb. 15, the administration decided to keep it open for another week for people who started an application before the deadline. The U.S. Health and Human Services Department also said people who were unable to submit an application due to technical difficulties on the website would receive an extension to enroll.

The administration has also said that it may grant a special enrollment period for uninsured people who will be forced to pay the individual mandate penalty for not having coverage.

Administration officials say they expect 9.1 million people to enroll in coverage by the end of the year, while the nonpartisan Congressional Budget Office had predicted 12 million enrollees for 2015.

Last April, White House officials announced that over 8 million people had signed up for Affordable Care Act plans for 2014. However, only 6.7 million were still enrolled by the end of the year.

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