"In too many cases, the American melting pot has been reduced to a simmer," Buchanan told 350 people at the Richard Nixon Library & Birthplace.

"If we want to assimilate new Americans -- and we have no choice if we are going to remain one nation -- we must slow down the pace of immigration," Nixon's former speechwriter said. "America is Balkanizing like never before."

In his speech, Buchanan promised if elected to reduce new entry visas to between 250,000 and 300,000 a year. In printed copies of his address, distributed to reporters in advance, he set the figure at 300,000.

In recent years, the United States has admitted between 700,000 and 800,000 legal, permanent residents each year, said Don Mueller, a spokesman for the Immigration and Naturalization Service.

Buchanan also pledged to make control of illegal immigration a national priority, though he offered no specific plans. "A country that cannot control its borders is not sovereign," Buchanan said to applause.

He criticized a U.S. policy that favors prospective immigrants who have relatives here, rather than their education and skills, and promised to change it.

Buchanan, who is to visit an Arizona border town Wednesday, blamed a host of other ills on what he characterized as excessive immigration.

He said crime and prison populations have increased in some regions where new immigrants have settled in large numbers, and he contended that immigration has depressed wages.

"At present rates, mass immigration reinforces ethnic subcultures, reduces the incentives of newcomers to learn the English language and extends the life of linguistic ghettoes that might otherwise be melded into the great American mainstream," he said.

At the same time, he heaped praise on new immigrants, saying he had met many of them while riding in cabs, dining in restaurants or traveling through airports during his campaigns.

"The contributions that immigrants make in small businesses and hard work in tough jobs that do not pay well merits our admiration and deepest respect," he said.

On the immigration dispute over Elian Gonzalez, the 6-year-old Cuban who was found lashed to an inner tube floating off the Florida coast Nov. 25, Buchanan said he favored bringing the boy's father and extended family to the United States for a hearing.

Elian's mother perished during their trip from Cuba, and the question of whether to send the boy back to that country has become a political issue. Elian's father has said he wants the boy back in Cuba, but Buchanan said, "We cannot take at face value what an individual says under Fidel Castro's thumb and his rule."

Buchanan said. "We should invite that man, the father of that boy, to the United States, say, 'Bring your whole family here and bring the boy's grandmother here and come and make the case in freedom that you want him back."'

"I think if necessary, we ought to make him an American citizen," Buchanan said.

Buchanan also sided with South Carolina residents who want to keep the Confederate flag flying over the Statehouse there.

Two of his great-grandfathers fought for the South in the Civil War and he considers the flag "a banner of heroism," he said. If state residents decide they want to keep the flag flying over the objections of those who consider it a racist affront, Buchanan said he would back them.

Buchanan, who worked in the Nixon White House, left the GOP last year to pursue the Reform Party presidential nomination.

Asked as he signed copies of his book how Nixon would have taken his departure from the party, Buchanan said: "I think Richard Nixon would understand why I did what I did, and I think he'd be very interested in how we're doing."

When John Taylor, executive director of the library, introduced Buchanan and reminded the audience that the candidate had left the GOP, he was interrupted by applause.