Don’t let a Border Patrol agent know you’ve got marijuana, regardless of whether you have a prescription, if you don’t want to lose it, the Border Patrol warns.

“We are not going out looking for it, but if an agent is helping a driver change a tire along the border and the driver lights up a joint, by law, we must seize it,” Chief Patrol Agent Daniel Hiebert said Monday at a press conference at the Bangor International Airport.

Maine voters in November made it legal for adults 21 or older to possess 2.5 ounces of marijuana. The state legalized the drug for medical use in 1999, but access wasn’t settled until 2009.

Marijuana possession still is illegal under federal law, which categorizes it as a Schedule I drug, just like heroin, morphine, LSD, peyote and oxycodone.

In 2013, after Colorado and Washington state legalized marijuana, the Obama administration shifted law enforcement priorities to focus on distribution rather than possession.

Now, under President Donald Trump, Hiebert said, “Our marching orders are to enforce the law.”

Since 2012, nearly 720 pounds of marijuana has been seized by Border Patrol agents in Maine, but no one has been prosecuted as the result of those seizures, according to agency statistics. In the 2016 fiscal year, there were 31 seizures, up from 15 in fiscal 2015. In fiscal 2017, which began on Oct. 1, 2016, there have been 19 seizures.

Hiebert’s advice to users of recreational or medical marijuana is simple: “Be careful. If you want to keep your marijuana, don’t do anything to get our attention.”

Border Patrol agents are responsible for securing the border between the 19 crossing stations in Maine, not at the border crossings themselves. Agents deal with people trying to cross the border illegally, people who are trying to smuggle people or drugs into Maine, and with people whose GPS has led them to lost a road where official border crossings used to be, Hiebert said.

The changes in Maine’s law and in society’s attitude toward marijuana have made recruiting qualified Mainers to the Border Patrol difficult. The agency wants recruits who have not used marijuana in two years and who have no relatives who grow recreational or medical marijuana. The Houlton Border Patrol sector, which includes all of Maine, should have 212 agents but has just 181 due to a lack of qualified applicants, according to Hiebert.