By GARDINER HARRIS and LAURIE GOODSTEIN
WASHINGTON — Standing in a room with the original Constitution, Declaration of Independence and Bill of Rights, President Obama on Tuesday declared that the United States should never give into fear but should continue to welcome immigrants and refugees because “that’s who we are.”
“Immigration is our origin story,” Mr. Obama said.
The speech, on the 224th anniversary of the ratification of the Bill of Rights, was intended as a rebuke to what the White House has called hateful talk against Muslims and immigrants by prominent Republicans. Mr. Obama gave the speech at the National Archives as 31 people from 25 different countries were sworn in as American citizens.
“You may come from teeming cities or rural villages. You don’t look alike. You don’t worship the same way,” Mr. Obama said to a group, with each of them clutching a tiny American flag. “But here, surrounded by the very documents whose values bind us together as one people, you’ve raised your hand and sworn a sacred oath. I’m proud to be among the first to greet you as my fellow Americans.”
The ceremony comes as 25 Republican governors have vowed to block the entry of Syrian refugees into their states, including some where large numbers of Syrians have settled in recent years. Mr. Obama has condemned such comments as contradicting American values.
The governors made their vow after the deadly terrorist attacks in Paris last month, and fears of terrorism have risen in the United States after the shooting this month in San Bernardino, Calif.
But Mr. Obama said that such fears are unfounded.
“In the Syrian seeking refuge today, we should see the Jewish refugee of World War II,” Mr. Obama said. Some Jewish refugee children were turned away from the United States during the period and were later killed by the Nazis.
Mr. Obama is struggling to fashion a message that reassures Americans that he is serious about battling the threat of the Islamic State and its terrorist messages while also avoiding xenophobia and alarmism. Polls suggest that many Americans believe he is not taking the threat from the Islamic State seriously enough, particularly after the deadly shooting in San Bernardino, Calif. Support among Republicans for banning Muslims is high.
To counter these dynamics, Mr. Obama gave a speech to the nation from the Oval Office on Dec. 6, visited the Pentagon on Monday and will visit the National Counterterrorism Center on Thursday, all to demonstrate that his administration is succeeding in its fight against terror and the Islamic State. But in each speech, Mr. Obama has yet to offer a new strategy, leaving even members of his own party grumbling.
On Tuesday, his speech was intended to combat the bigotry and anti-immigrant fervor that has accompanied the concern about the Islamic State. He said that immigrants and refugees had been targeted before, including Catholics whose loyalty was questioned and Chinese immigrants who were banned for a time. He mentioned the internment of Japanese-Americans during World War II as particularly grievous mistake.
“We succumbed to fear. We betrayed these documents. It’s happened before,” Mr. Obama said. “And the biggest irony is that those who betrayed these values were themselves the children of immigrants.”
“How quickly we forget,” Mr. Obama said. “One generation passes, two generations, and suddenly we don’t remember where we came from.”
Mr. Obama did not mention Donald J. Trump, who is leading in most polls in the Republican presidential primary race and has called for Muslims to be blocked from entering the United States. Nor did he specifically call out Senator Ted Cruz of Texas, another Republican candidate, who has said he plans to introduce legislation barring Syrian Muslim refugees from entering the United States, or Jeb Bush, also a Republican presidential candidate, who has suggested that the authorities allow only Syrian Christians into the country.
But his targets were plain.
“We can never say it often or loudly enough: Immigrants and refugees revitalize and renew America,” Mr. Obama said.
Also this week, the White House is holding a series of meetings with religious leaders to discuss ways the administration is working to address discrimination, harassment and episodes of hate while promoting pluralism and religious freedom.
Officials from both the Obama and George W. Bush administrations “have observed that the kind of offensive, hateful, divisive rhetoric that we’ve seen from a handful of Republican candidates for president is damaging and dangerous,” Josh Earnest, the White House press secretary, said in a briefing on Monday.
On Monday evening, senior White House advisers met with about a dozen American Muslim leaders who had been invited to discuss the climate of rising anti-Muslim bigotry and hate. One Muslim leader who attended, Farhana Khera, the executive director of Muslim Advocates, a national legal advocacy organization based in San Francisco, said she had left the meeting feeling “very heartened.”
“They were expressing a genuine concern about the environment of anti-Muslim hate and violence, and really wanted to hear from the community about the impact and what the federal government can do,” she said.
The White House advisers included Valerie Jarrett, a senior aide; Cecilia Muñoz, the director of the Domestic Policy Council; Melissa Rogers, the head of the faith-based initiative office; and Benjamin J. Rhodes, a deputy national security adviser.
Ms. Khera said that since the Paris attacks, her office had documented an unprecedented series of hate crimes against Muslims and Muslim houses of worship — nearly 50 episodes, or an average of two a day. She said she had asked the president’s advisers to urge the federal government to prosecute “the most egregious” attacks as hate crimes.
“We believe the level of hate violence has reached a crisis point, and that’s why it’s crucial that the federal government needs to send a message to the public, in the strongest terms, that these hate crimes will be prosecuted to the fullest extent of the law,” Ms. Khera said.
She said one proposal that seemed to have traction at the meeting was for the Education Department to issue guidance to schools and educators on dealing with anti-Muslim hate, harassment and bullying of students.
The group also discussed, she said, whether federal officials should do more to explain to the public what law enforcement officials have found: that extremist beliefs and support for the Islamic State are being spread not by mosques, which nevertheless are often the targets of hate crimes, but over the Internet and social media.
A meeting with Sikh leaders was also held on Monday. And on Thursday afternoon, members of an array of religious and civil society groups will meet to discuss ways to promote religious pluralism, officials said.
In all these meetings, administration officials will emphasize their commitment to “standing up and continuing to speak out in support of the values that are central to the founding of our country, but also critical in terms of advancing our national security interests,” Mr. Earnest said.