WASHINGTON—A surge of high-potency marijuana illegally smuggled into the United States from Canada is fuelling a rise in drug dependency among young Americans, the Bush administration's drug czar says.

A frustrated John Walters, the director of the U.S. National Drug Control office, yesterday signalled Washington's ongoing irritation with what it sees as a lax attitude toward drug crimes north of the border, something that has forced it to redeploy drug patrols from the Mexican border to its northern flank.

Walters conceded yesterday American authorities are making no dent in the flow of Canadian pot and he said Canadian police and prosecutors have told him lenient Canadian courts are a root of the problem.

"The big new factor on the scene ... is the enormous growth of high potency marijuana from Canada," Walters said.

"This is a problem. It requires joint action and we will continue to work with Canadian government on this.

"But right now, the trend (does not show) this is getting smaller."

The Bush administration has been vocal in its concern over Canadian "grow ops," ecstasy manufacturers and a move by the past Liberal government to decriminalize marijuana possession, but Walters' message takes on a special urgency now.

The problem U.S. President George W. Bush has with drug smugglers on both his southern and northern borders is expected to be raised when he meets with Prime Minister Paul Martin and Mexican President Vicente Fox at a trilateral summit in Waco, Texas, on March 23.

Secretary of State Condoleezza Rice — who has still not set a date for a Canadian visit — also raised drug-related violence on the Mexican border when she met yesterday with Fox in Mexico City.

Walters also mentioned the slaying of the four Alberta RCMP officers last week, offering condolences to their families and community members of Mayerthorpe, Alta., on behalf of the White House.

But he said the proliferation of grow ops is cause for concern not only in Western Canada, but also Toronto.

He was careful not to criticize the Canadian judicial system, but he repeated complaints he has heard from prosecutors and police officials in British Columbia and Toronto.

"I've talked to prosecutors in Canada over the past several years and they have stressed to me they don't believe they have sufficient sanctions against those involved in trafficking," Walters said.

"The law in some provinces is that unless you actually commit a violent crime against another individual, the tendency is for you not to get serious jail time."

He said the same trafficking crimes bring serious consequences in the United States and traffickers are often prosecuted under conspiracy and money-laundering laws because they often do not get their hands dirty in the actual transit of drugs where the violence occurs.

U.S. courts often impose mandatory minimum sentences — a practice Walters acknowledged is controversial — but a measure he said was needed to hold accountable "those who cause pain.

"Without the ability to use more extensive enforcement pressure, they (Canadian authorities) are concerned about how this will continue to grow," he said.

Last weekend, The New York Times published an extensive article chronicling the flow of so-called "B.C. Bud," a high-potency Canadian-grown marijuana now much in demand in the U.S. and Europe, across the British Columbia-Washington border.

The newspaper pegged the value of the Canadian cultivation and smuggling operation at $7 billion per year and Walters called the B.C. pot "dangerous and addictive."

Walters said the THC content in typical marijuana found in the United States over the past five years has gone from one to two per cent to a THC content of eight to nine per cent.

THC (tetrahydrocannabinol) is the active ingredient in marijuana that creates the "buzz" users seek.

Some varieties go up to 14 to 15 per cent THC level and some specially cultivated pot grown in Canada can offer THC levels of 25 to 30 per cent, Walters said.

Walters stressed that marijuana cannot be classed as a "soft drug" as it was in decades past.

"Of the 7 million people we have to treat in the United States, from the age of 12 and up, for dependence or abuse, over 60 per cent have marijuana as their primary dependence," he said.

Of the 5 million Americans aged 12-17 who use marijuana, he said, already 1 million are at the point where they need intervention or treatment.

"That is not the way marijuana use was a decade ago, a few decades ago. That's why the ignorance of people who think this is not a drug you have to be concerned about is a problem."

Walters said the main repercussion for both countries is the health and well-being of its youth, but he said the Canadian drug traffic has forced the U.S. to institute heavier border surveillance at a time when the two countries should be working toward freeing restraints at the border to try to speed commerce between the two nations, he said.