President Donald Trump's Environmental Protection Agency was accused of being a pesticide "cheerleader" last week after the agency said it would not approval labels that say that glyphosate — the active ingredient in Roundup and other weedkillers — is known to cause cancer.

In a statement released Thursday announcing the move, the EPA dug in on its assertion that glyphosate does not cause cancer, though critics have said that is "an industry-friendly conclusion that's simply not based on the best available science."

The new guidance takes aim at California's 2017 move, in adherence with its Proposition 65, to add glyphosate to its list of chemicals known to cause cancer and require warning labels. The state cited the World Health Organization's International Agency for Research on Cancer 2015 assessment that glyphosate is "probably carcinogenic to humans."