A congressional committee yesterday recommended that the U.S. border with Mexico be sealed. It cited "potentially explosive" levels of illegal immigration.

Overall illegal immigration already accounts for 15 to 25 percent of the nation's population growth, according to estimates by the House Select Committee on Population, and "if current low U.S. fertility rates continue, eventually all U.S. population growth will be attributable to immigration - mostly illegal - unless something is done."

The committee admitted that accurate figures are extremely difficult to get, but its chairman, Rep. James H. Scheuer (E-N.Y.), said, "We do have enough statistics about illegal immigration from Mexico to learn that it is a potentially exploxive situation.

"We learned that 60 percent of hundreds of thousands of illegal aliens who cone to the United States each year are from Mexico . . . The typical Mexican illegal alien has his choice among a variety of ways to sneak across the border," Scheuer said.

As a result, Scheuer said his 15-member committee, which includes Resident Commissioner Baltasar Corrada (D-Puerto Rico), "advocates a firm, hard sealing of the border" between the United States and Mexico.

But Scheuer said he does not know how such a border sealing might take place. "That'll have to be left to the appropriate law enforcement agencies," he said.

In issuing its warning about illegal immigration, the committee said in athe report: "Currently the U.S. population is growing slowly (at a rate perhaps 1.0 percent per cent) and 25 percent to 50 percent of this is attributable to legal and illegal immigration.

"If current low U.S. fertiltiy rates continue, eventually all U.S. popluation growth will be attributable to immigration - mostly illegal, assuming migration - mostly illega, assuming continuation of present inadequate border cotrols."

Scheuer said after his press conference that he expected the report to spark controversy. He was right.Reaction came quickly from representatives of the nation's Spanish-speaking community.

"It sounds to me like this particular committee is taking a very anti-Chcano, anti-Mexican stand," said Raul Yzaguirre, national director of the Washington-based National Council of La Raza, a Hispanic civil rights organization.

"I don't think there's any way you can seal the border. And even if you could, that kind of law enforcement is the wrong way to approach th e[illegal immigration] problem.

"Following those proposals would create serious problems between the United States and Mexico at a time when the United States greatly needs Mexico, because it can become a major source of U.S. oil," Yzaguirre said.

Scheuer vigorously denied that his committee's recommendations on curbing illegal and better regualting legal immigration are anti-Chicano. Instead, he said the 16 recommendations made by the committee are "compassionate and humanitarian." Besides "selling the border," the other major recommendations include:

Reforming the visa system "to reduce the widespread practice of visa abuse by vistors or students who overstay their visas and take jobs in violation of U.S. law."

Toughening deportation laws for legal immigrants who become welfare recipients.

Passing legislation "to make U.S. sponsors of legal immigrants financially responsible for their maintenance."

Establishing a "fraudulent document laboratory" in the Immigration and Naturalization Service "to help control the apparently large market for counterfeit Social Security cards" and other documents "used by illegal immigrants to legitimize their pressence."

Working with the Mexican government to establish a more effective birth control program in Mexicao, and to improve employment and other economic opportunites within that country.

Passing legislation "to enable the return to Mexico fo rincarceration any Mexican for incarceration any Mexican national convicted of a crime in the U.S."