As the 4/20 weekend kicked off, federal officials issued new guidance for would-be U.S. citizens that says working in the cannabis industry, even in states where the drug has been legalized, could be grounds for rejection during the naturalization process.

Observers saw the move on 4/20, the unofficial holiday for cannabis enthusiasts, as a hurdle set up by the Trump administration for newcomers rather than one targeted at the nascent marijuana industry in the more than 30 states that have legalized some form of the drug.

U.S. Citizenship and Immigration Services publicized the new guidance in a statement Friday.

"The policy guidance ... clarifies that an applicant who is involved in certain marijuana-related activities may lack good moral character if found to have violated federal law, even if such activity has been decriminalized under applicable state laws," the agency, an arm of the Department of Homeland Security, stated.

The fine print of the guidance states that participation in the cannabis industry "continues to constitute a conditional bar to GMC [good moral character] for naturalization eligibility, even where such activity is not a criminal offense under state law."

"Possession of marijuana for recreational or medical purposes or employment in the marijuana industry may constitute conduct" that would prohibit naturalization, the guidance states.

A cannabis worker trims a cannabis flower at Loving Kindness Farms in Gardena, Calif., on April 4, 2019. Richard Vogel / AP

"I don’t think this is about marijuana at all," said Michael Collins, national affairs director of the Drug Policy Alliance. "I think this is about them using the war on drugs to go after migrant community and that’s what they’ve been doing since Day 1."

Collins compared the policy guidance, first reported by Marijuana Moment, to President Donald Trump's insistence on a wall between the United States and Mexico, which the president has said would stop the flow of drugs to the country.

"This administration has used the war on drugs to persecute the migrant community, from building the wall to going after migrants for minor drug offenses," Collins said.

Earlier this month, Colorado attorneys representing two immigrants who work in the legal marijuana industry accused the Trump administration of blocking the naturalization of the pair.

It's not yet clear how strict authorities will be. NBC News reached out to USCIS but did not receive a response.

"The Department of Homeland security sees this is another excuse to deport people," Collins said. "To deal with this issue you really need to take marijuana policy out of the hands of the federal government."