WASHINGTON — President Barack Obama is defending the work of the Environmental Protection Agency, saying it performs a vital role protecting the environment and moving the country toward energy independence.

Obama spoke Tuesday during his first-ever visit to the EPA, seeking to boost morale at an agency that has been a target for Republicans. Several GOP presidential candidates have questioned the science of global warming and said they'd overturn EPA regulations that harm the economy.

The president said that improving the environment and improving the economy shouldn't be contradictory goals, and he questioned those who say regulations are not needed.

He said environmental regulations are responsible for cleaning up badly polluted sites, and he said the EPA should be commended for making vehicles more fuel efficient and promoting clean air and water.