"We've recently heard from many loyal Apple customers who were disappointed to learn that we had removed our products from the EPEAT rating system," Apple's senior vice president for hardware engineering, Bob Mansfield, said in a statement. "I recognize that this was a mistake. Starting today, all eligible Apple products are back on EPEAT."

Late last month, Apple notified EPEAT that it would stop submitting its products for certification. The international group's ratings were developed in collaboration with industry leaders, including Apple, and are used by some governments to determine which gadgets are environmentally friendly enough to be bought with public money.

EPEAT primarily measures a product's recyclability and energy efficiency. The certification covers laptops, desktops and monitors, but not tablets and phones.

Apple would not say why it had left the green certification system, but it was widely speculated that its new line of MacBook Pro laptops, which had not been reviewed by EPEAT, might be too difficult to recycle to earn the certification. Unlike in previous models, the battery of the MacBook Pro with Retina Display is glued to its metal case.

Reviewers have complained the laptops are nearly impossible to disassemble.

Earlier this week, Apple declined to comment on those allegations.

In its Friday statement, Apple renewed its commitment to greener gadgets.

"It's important to know that our commitment to protecting the environment has never changed, and today it is as strong as ever," the statement says.

Apple also calls on the group to update its standards to reflect other areas.

" ... Our engineering teams have worked incredibly hard over the years to make our products even more environmentally friendly, and much of our progress has come in areas not yet measured by EPEAT," the statement says.

"For example, Apple led the industry in removing harmful toxins such as brominated flame retardants (BFRs) and polyvinyl chloride (PVC). We are the only company to comprehensively report greenhouse gas emissions for every product we make, taking into account the entire product life cycle. And we've removed plastics wherever possible, in favor of materials that are more highly recyclable, more durable, more efficient and longer lasting. Perhaps most importantly, we make the most energy-efficient computers in the world and our entire product line exceeds the stringent ENERGY STAR 5.2 government standard. No one else in our industry can make that claim."

The environmental group Greenpeace applauded Apple's decision but said the company still needs to prove to the public that its new laptops can be recycled.

"A large and growing number of Apple customers have challenged the company to be an environmental leader, whether that is by rejoining EPEAT, eliminating toxic chemicals from its products, or powering its iCloud with renewable energy," the group said in a statement e-mailed to CNN.

"We await more details that ensure that future versions of Apple's computers will be built with easily removable, recyclable and upgradable parts, unlike the current MacBook Pro. These design changes would make for a greener Apple product."