President Obama announced that the Obamacare marketplace saw 670,000 people sign up for coverage Thursday, its biggest open enrollment day ever.

“Yesterday was the biggest day ever for Healthcare.gov. More than 670,000 people signed up to get covered, and more are signing up by the day,” Obama said Friday during his introductory remarks at his year-end press conference.

The Department of Health and Human Services had announced Thursday evening that the open enrollment deadline for Jan. 1 coverage had been extended two business days, citing “extraordinary” demand.

The enrollment boost comes as Republicans are working on their plan to repeal the Affordable Care Act in the new Congress next year, with GOP leaders signaling it will be their top priority January.