(Recasts with comments from Obama)
By Roberta Rampton and Susan Cornwell
WASHINGTON, Dec 20 (Reuters) - President Barack Obama on Friday defended his administration's decision to delay for some people the requirement to buy medical insurance under his healthcare law, explaining that the rollout of his signature domestic policy is a "messy process."
Officials said late on Thursday that people whose insurance plans were canceled because of new standards under the law may be able to claim a "hardship exemption" to the requirement that all Americans must have coverage by March 31, or face a penalty.
The sudden change came four days before the deadline to sign up for coverage, which starts on Jan. 1 under the law known as Obamacare. It threatened to further dampen enthusiasm for the law, which has suffered a chaotic rollout that has driven Obama's public approval numbers to historic lows.
Republicans seized on the latest announcement as further proof that Obamacare is unworkable, but Obama said it was just a bump in the road.
"I've said before, this is a messy process," Obama said during a news conference before leaving for Hawaii for the holidays. "When you try to do something this big, affecting this many people, it's going to be hard."
Obama also pointed to a surge in enrollment, after the disastrous launch of the glitch-ridden HealthCare.gov website resulted in fewer than 27,000 people signing up through the federal marketplace in October.
Officials said that more than 1 million people have signed up so far for new coverage under Obamacare through state and federal marketplaces.
Still, there are lingering problems. Consumers were unable to access HealthCare.gov for a few hours during the middle of the day on Friday, a critical time before the Dec. 23 deadline. Officials said they needed to repair a website error that occurred overnight.
'WE SCREWED IT UP'
The rocky rollout of the law since Oct. 1 has been embarrassing and politically damaging. Obama again accepted blame, saying: "Since I'm in charge, obviously we screwed it up."
Part of the recent backlash came when millions of people received policy cancellation notices, forcing Obama to apologize for a promise he made that people who liked their insurance policies could keep them under the reforms.
U.S. officials estimated that fewer than 500,000 people would be affected by this delay in the so-called individual mandate. The mandate is a core part of the 2010 Affordable Care Act that aims to provide coverage to millions of uninsured Americans.
However, the announcement raises fairness questions, as it gives a subset of Americans relief from the requirement to buy insurance. "It is the beginning of the end of the individual mandate," said Republican Senator Lindsey Graham of South Carolina.
Republicans have opposed the healthcare law as an unwarranted expansion of the federal government.
Insurance industry trade group, America's Health Insurance Plans, criticized the change that could divert more consumers away from the new plans offered under Obamacare.
"This latest rule change could cause significant instability in the marketplace and lead to further confusion and disruption for consumers," AHIP President and CEO Karen Ignagni said in a statement. (Additional reporting by Susan Heavey, Jackie Frank, Terry Baynes and Lewis Krauskopf; Writing by Karey Van Hall; Editing by Grant McCool and Christopher Wilson)