US Attorney General Jeff Sessions has rescinded an Obama-era policy that eased enforcement of federal marijuana laws, in a move that critics say is the latest example of Trump administration policies that could hurt communities of colour who have historically been targeted by anti-drug directives.

An official at the Justice Department said that the policies put in place by the administration of President Barack Obama to ease federal enforcement of recreational marijuana distributors abiding by state laws "created a safe harbour for the marijuana industry to operate in these states and... there is a belief that that is inconsistent with what the federal law says."

Federal prosecutors have now been instructed to disregard that Obama policy, and have been instructed to approach recreational marijuana dispensaries operating in accordance to state law in the same way that they would any other case.

"It was interpreted as a safe harbour for individuals," Mr Sessions said of the Obama-era policies. "This memo does not have safe harbours in it."

During the Obama era, several states moved to pass recreational marijuana laws, including Colorado and Washington states. And, just days ago, California opened up its recreational marijuana market -- the largest state in the country so far to do it.

Critics of the new Department of Justice directive point out that America's so-called war on drugs has resulted in skyrocketing incarceration rates in the country, predominantly among populations of black and brown Americans. The arrests and imprisonment that has resulted from those drug policies, including those surrounding marijuana, have damaged communities, disenfranchised would-be voters, and denied basic services to those who have been swept up, they say. But, this latest policy is in-line with previous anti-drug sentiments Mr Sessions has expressed, they say, including a memo earlier sent this last year to federal prosecutors pulling back a different Obama-era policy that allowed them to pursue lighter sentencing for crime suspects in certain circumstances (including drug violations).

In pictures: 4/20 Marijuana world rallies Show all 26 1 /26 In pictures: 4/20 Marijuana world rallies In pictures: 4/20 Marijuana world rallies A man wears a marijuana leaf mask during the annual 4/20 cannabis culture celebration at Sunset Beach in Vancouver, British Columbia AP In pictures: 4/20 Marijuana world rallies A lady smokes marijuana on Parliament Hill on 4/20 in Ottawa, Ontario Getty Images In pictures: 4/20 Marijuana world rallies James Reed smokes a joint during the Denver 420 Rally at Civic Center Park in Denver, Colorado Getty Images In pictures: 4/20 Marijuana world rallies People sign a 4/20 sign on Parliament Hill on in Ottawa, Ontario Getty Images In pictures: 4/20 Marijuana world rallies A woman smokes marijuana on Parliament Hill on 4/20 in Ottawa, Ontario. Polling released showed strong support in Canada for a government drive to legalise recreational use of marijuana, but many would like the proposed minimum age for consumption to be raised. Sixty-three percent of respondents told the Angus Reid Institute they support legalisation Getty Images In pictures: 4/20 Marijuana world rallies A man smokes marijuana during the annual 4/20 marijuana rally on Parliament Hill in Ottawa, Ontario, Canada Reuters In pictures: 4/20 Marijuana world rallies Demonstrators smoke marijuana during the '4/20 Santiago' rally in favour of legalisation in front of the La Moneda presidential palace in Santiago, as part of the Global Marijuana March which is being held in hundreds of cities worldwide Getty Images In pictures: 4/20 Marijuana world rallies People play with a mock marijuana joint during a 4/20 party to demand legalisation and to celebrate marijuana culture outside the Senate building in Mexico City, Mexico Reuters In pictures: 4/20 Marijuana world rallies Adam Eidinger, co-founder of DCMJ, hands out free marijuana joints to DC residents who worked on Capitol Hill as part of the 1st Annual Joint Session to mark '4/20' day and promote legalising marijuana on Capitol Hill in Washington, DC Getty Images In pictures: 4/20 Marijuana world rallies In pictures: 4/20 Marijuana world rallies Police arrest Rachel Ramone Donlan after she handed out free marijuana joints to DC residents who worked on Capitol Hill as part of the 1st Annual Joint Session to mark '4/20' day and promote legalising marijuana on Capitol Hill in Washington, DC AFP/Getty Images In pictures: 4/20 Marijuana world rallies Police arrest Rachel Ramone Donlan after she handed out free marijuana joints to DC residents who worked on Capitol Hill as part of the 1st Annual Joint Session to mark '4/20' day and promote legalising marijuana on Capitol Hill in Washington, DC Getty Images In pictures: 4/20 Marijuana world rallies Thousands of people gather to smoke marijuana during the '420 Santiago'rally in front of the La Moneda presidential palace in Santiago Getty Images In pictures: 4/20 Marijuana world rallies People attend the Denver 420 Rally at Civic Center Park in Denver, Colorado Getty Images In pictures: 4/20 Marijuana world rallies Kevin Barron and Lasean Moore of Raleigh, North Carolina, share a joint during the Denver 420 Rally at Civic Center Park in Denver, Colorado Getty Images In pictures: 4/20 Marijuana world rallies Nic Ruhl takes a pull on a giant hand rolled joint at precisely 4:20pm MDT during the Denver 420 Rally at Civic Center Park in Denver, Colorado Getty Images In pictures: 4/20 Marijuana world rallies Various cannabis paraphernalia on display at a vendor's stall during the Denver 420 Rally at Civic Center Park in Denver, Colorado Getty Images In pictures: 4/20 Marijuana world rallies Mo Banez, of Austin, Texas, lights a joint during the Denver 420 Rally at Civic Center Park in Denver, Colorado Getty Images In pictures: 4/20 Marijuana world rallies A man displays a large container of cannabis during the Denver 420 Rally at Civic Center Park in Denver, Colorado. The rally, held annually, is a celebration of both the legalisation of cannabis and cannabis culture. Colorado is one of twenty-six U.S. states along with the District of Columbia that has legalised the use of cannabis either recreationally or medically AFP/Getty Images In pictures: 4/20 Marijuana world rallies Sitting in small groups on mats shaded by trees in the Rose Garden just across from the Knesset, participants lit up as the clock struck 4:20 for the local version of the traditional worldwide April 20 pro-marijuana events, known as '420' rallies Getty Images In pictures: 4/20 Marijuana world rallies An Israeli smokes a marijuana joint in Jerusalem during a rally at the Rose garden Getty Images In pictures: 4/20 Marijuana world rallies Sitting in small groups on mats shaded by trees in the Rose Garden just across from the Knesset, participants lit up as the clock struck 4:20 for the local version of the traditional worldwide April 20 pro-marijuana events, known as '420' rallies Getty Images In pictures: 4/20 Marijuana world rallies An Israeli girl poses with a mock marijuana joint in Jerusalem during a rally at the Rose garden, to celebrate 420 and to express their defiance of current laws Getty Images In pictures: 4/20 Marijuana world rallies aelis pass around a marijuana joint in Jerusalem during a rally at the Rose garden, to celebrate 420 and to express their defiance of current laws Getty Images In pictures: 4/20 Marijuana world rallies An Israeli smokes a marijuana joint in Jerusalem during a rally at the Rose garden, to celebrate 420 and to express their defiance of current law Getty Images In pictures: 4/20 Marijuana world rallies An Israeli smokes a marijuana joint in Jerusalem on April 20, 2017 during a rally opposite the Knesset to celebrate 420 and express defiance of current laws AFP/Getty Images

"Sessions has not proven himself to be someone who cares about these communities," Maria Mcfarland Sánchez-Moreno, the executive director at the Drug Policy Alliance, told The Independent. "This is more proof about the callousness that he has, and the willingness, and interest, in pursuing policies that will harm, overwhelmingly, people of colour."

There were roughly eight million marijuana arrests between 2001 and 2010, according to an estimate by the American Civil Liberties Union, accounting to roughly one bust every 37 seconds. That level of enforcement resulted in an estimated $3.6 billion a year spent on policing the drug, that study found, even though the availability of the drug remained largely unchanged. Of the arrests that resulted from those busts, black people were disproportionately impacted, and were 3.73 times more likely as white people to be arrested for marijuana possession.

But, as California, Colorado, and Washington State -- among other states-- illustrate, the push for legalisation has been gaining momentum. All told, seven states and the District of Columbia have legalised recreational marijuana in some form of another, wielding a staggering windfall of extra tax dollars counted into the hundreds of millions a year.

Republicans and Democrats alike reacted to Mr Sessions' change in policy with frustration. Jay Inslee, the Democratic governor of Washington, vowed to protect his state laws against "federal infringement". Meanwhile, Colorado's Republican Senator Cory Gardner said that he was blind sided by the new policy.

"I am prepared to take all steps necessary, including holding DOJ nominees, until the Attorney General lives up to the commitment he made to me prior to his confirmation," Mr Gardner wrote on Twitter.

Representative Dana Rohrbacher, a Republican from California, framed the decision as a "gift" to drug cartels.

"The attorney general of the United States has just delivered an extravagant holiday gift to the drug cartels. By attacking the will of the American people, who overwhelmingly favour marijuana legalisation, Jeff Sessions has shown a preference for allowing all commerce in marijuana to take place in the black market," Mr Rohrbacher wrote in a statement, " which will inevitably bring the spike in violence he mistakenly attributes to marijuana itself."

It is not clear what will happen now that the new marching orders have been handed down by the Department of Justice. The new policy doesn't explicitly order any district attorneys to focus on enforcement of federal marijuana laws in states that have legalised the drug for recreational uses, leaving open the possibility that states with legalised marijuana could see a patchwork of enforcement efforts, depending on the district. Congress has the opportunity to act later this month as well, should it choose to, and could extend budget restrictions on federal enforcement of medical marijuana dispensaries, should enough of an appetite exist to rebuke the attorney general.

"In terms of the merit of what this means, it's one of those situations where time will only tell if this actually changes the situation on the ground," Alex Kreit, an expert on federal drug policy at Thomas Jefferson School of Law, told The Independent.

One federal law enforcement official said his approach would not change. US Attorney Bob Troyer, who oversees Colorado, said in a statement that the Department of Justice had directed prosecutors to follow “principles that have long governed all of our prosecution decisions”.

“The United States Attorney’s Office in Colorado has already been guided by these principles in marijuana prosecutions — focusing in particular on identifying and prosecuting those who create the greatest safety threats to our communities around the state,” Mr Troyer said. “We will, consistent with the Attorney General’s latest guidance, continue to take this approach in all of our work with our law enforcement partners throughout Colorado”.

Mr Kreit noted that differing enforcement standards would leave citizens with a bizarre legal landscape to navigate.