Drug mafias in Mexico have used a more pure and potent heroin to become the second-largest supplier to users in the United States, according to a published report.

The Washington Post quotes U.S. anti-drug officials in Tuesday's editions as saying that Mexico now accounts for nearly 42 percent of all heroin brought into the United States, second only to Colombia.According to officials of the U.S. Drug Enforcement Agency, the Mexican drug mafias control virtually all heroin sales west of the Mississippi River, said the Post.

Meanwhile, the newly retired commandant of the U.S. Coast Guard, Adm. Robert Kramek, complained to the Post that tight budgets and partisan bickering has severely hampered the war on drug smugglers.

"We don't have the will, between the administration and Congress to win this thing," he told the paper.

He said a strategy drawn up by retired Gen. Barry R. McCaffrey, the White House drug czar, would win the war on drugs, but not enough money has been provided to make it work.

"As a result we're not going to do any better this year than we did last year," said Kramek, whose force has been responsible for much of the drug interdictions. He retired last week after 41 years in the Coast Guard including its commandant over the last four years.

The emerging trend in Mexico's drug trade points to a global shift. In 1992, Asian organizations captured 90 percent of the U.S. heroin market, a figure that has since dropped to 28 percent.

The number of heroin users in the United States has risen from 500,000 to 600,000 over the past two years, the Post said.