WASHINGTON -- Republicans in Washington are threatening to cut U.S. funding for the World Health Organization's cancer research program over its finding that the herbicide Roundup is probably carcinogenic to humans.

House Science Committee Chairman Lamar Smith says the 2015 finding by the International Agency for Research on Cancer was fundamentally flawed and relied on cherry-picked science. The Texas lawmaker says he has concerns about bias within the program, raising questions about whether it should receive government money.

The group's 2015 findings differ from those of the Environmental Protection Agency, which concluded in December that Roundup is not likely to cause cancer at typical levels of exposure.

Roundup, made by Monsanto, is the world's most widely used herbicide and has been sprayed on fruits and vegetables since the 1970s.