King, R-Iowa, told CNN today, "I meant exactly what I said."
"I've been to Europe and spoken on this issue ... I've said to them, you cannot rebuild your civilization with somebody else's babies," King said on CNN. "You've got to keep your birthrate up, and ... you need to teach your children your values."
King, who calls himself a "champion of Western civilization," argued that it is a "superior civilization and we want to share it with everybody."
"If you go down the road a few generations or maybe centuries with the intermarriage, I'd like to see an America that's just so homogeneous," King, 67, told CNN. "I think there's far too much focus on race, especially in the last eight years."
Asked whether a Muslim American, an Italian-American and a German-American are equal, he replied, "I'd say they're all created in the image of God and they're equal in his eyes. If they're citizens of the United States, they're equal in the eyes of the law."
King continued, "Individuals will contribute differently, not equally to this civilization and society. Certain groups of people will do more from a productive side than other groups of people will."
His comments received the support of former KKK imperial wizard David Duke, who tweeted, "GOD BLESS STEVE KING" and "sanity reigns supreme" in King's congressional district.
But Jeff Kaufmann, the chairman of the Iowa Republican Party, distanced himself from King's tweet.
"First of all, I do not agree with Congressman King's statement. We are a nation of immigrants, and diversity is the strength of any nation and any community," Kaufmann said in a statement released this morning. "Regarding David Duke, his words and sentiments are absolute garbage. He is not welcome in our wonderful state."
King's tweets and interview drew the ire of other fellow Republicans.
"What exactly do you mean? Do I qualify as 'someone else's baby?'" tweeted Florida Rep. Carlos Curbelo, the son of two immigrants who fled Cuba in the 1960s.
"Is it worth making the obvious point that what American history has been about is 'restoring' ourselves with 'somebody else's babies?'" conservative columnist Bill Kristol asked.
"Republican Congressman Steve King's vile racism has no place in decent society, much less in the U.S. Congress," Drew Hammill, a spokesman for House Minority Leader Nancy Pelosi, D-Calif., said in a statement. "The GOP leadership must stop accommodating this garbage and condemn Congressman Steve King's statements in the strongest and most unequivocal terms."
"The speaker clearly disagrees and believes America's long history of inclusiveness is one of its great strengths," House Speaker Paul Ryan's press secretary AshLee Strong said in a statement.
King's office did not immediately respond to ABC News' request for comment.
King's history of controversial comments
This isn't the first time King, who was elected to the House in 2002, has found himself in hot water over his views on race.
"I'd ask you to go back through history and figure out where are these contributions that have been made by these other categories of people that you're talking about?" he added. "Where did any other subgroup of people contribute more to civilization?"
In 2013 he implied that the vast majority of unauthorized immigrants brought into the U.S. as children are drug mules.