One of Mexico's last remaining chunks of virgin jungle is threatened by forest fires that have cloaked the country in smoke, officials said.

Deputy Environment Minister Victor Villalobos said his ministry counted 41 separate blazes in the remote Chimalapas rain forest of southern Oaxaca state and that Mexico would intensify its firefighting efforts in the region."It will be the most substantial fire in area and, above all, in all the damage it is causing," Villalobos said Wednesday.

Villalobos said he expected that help requested from the United States would also be channeled into Chimalapas.

"That is where we are concentrating national help and eventually whatever help comes from the United States," he said.

Mexico is ranked as the fourth most biologically diverse country in the world, but ecologists say it has less than 5 percent of its original rain forest left.

Fed by unusually dry conditions brought by the El Nino warm wa-ter current in the Pacific, forest fires have devastated huge tracts of countryside in Mexico and Central America, sending smoke clouds as far north as Texas.

The Environment Ministry said in a statement that up to May 13, it had counted 10,656 separate fires that have burned 712,500 acres. It said 23 percent was wooded, while the rest was pasture.

The blazes have killed at least 30 firemen this year and have exacerbated already heavy pollution in the capital of Mexico City and other large cities.

Crops have also suffered from prolonged drought, and Finance Ministry figures revealed this week showed a 6 percent drop in the first quarter of 1998 in agricultural production.

On May 14, Mexican officials finally threw in the towel and asked for assistance from the United States.