WASHINGTON — President Obama urged Americans on Wednesday to remain resilient against threats posed by the Islamic State, calling on the nation not to give in to fear and to remember the ‘‘Boston Strong’’ message nearly three years ago after the bombing at the Boston Marathon.

Obama vowed that the United States is ‘‘going to win’’ in its fight against terrorist groups and said the Islamic State’s ‘‘barbarism only stiffens our unity and determination to wipe this vile terrorist organization from the face of the earth.’’

But in his brief remarks to reporters after meeting with a large group of national security aides at the CIA headquarters in Langley, Va., Obama also emphasized that Americans must not panic and must remain true to their values in the face of gruesome terrorist attacks around the world.

‘‘I want to remind Americans again what Boston taught us: how to be strong, how to be resilient,’’ Obama said, flanked by Cabinet members, including Vice President Biden, Secretary of State John F. Kerry, Homeland Security Secretary Jeh C. Johnson, and National Security Adviser Susan E. Rice. ‘‘We have to refuse to give in to fear. We have to stay true to our values of liberty and diversity and openness.’’

The Boston Marathon bombing on April 15, 2013, killed three spectators of the race and injured more than 260 others.

That attack was carried out by a pair of Chechen brothers, Tamerlan and Dzhokhar Tsarnaev, whose family had entered the United States on a tourist visa and subsequently received asylum protections.

Since a series of recent attacks in Paris, San Bernardino, Calif., and Brussels, Obama has sought to temper public fears over terrorism and the expanding reach of the Islamic State, which claimed responsibility for the two European attacks. The San Bernardino killers were said to claim inspiration from the militant group but there is no evidence of a direct connection.

Yet amid criticism from Republicans in an election year, Obama has repeatedly sought to counter suggestions from the candidates that the United States ban Muslims and take other steps to block immigrants.

Obama met for more than two hours with about two dozen aides at Langley and several others on a secure video link. The president has held a series of similar meetings at other federal agencies involved in the campaign against the Islamic State, the security situation in Iraq, and the civil war in Syria.

After the meeting, Obama maintained that the US-led coalition has made progress in the fight against the terrorist group.

‘‘We have momentum, and we intend to keep that momentum,’’ he said. He cited 11,500 airstrikes that have disrupted the opposition’s movements and the killing of Islamic State commanders.

‘‘In the face of madmen who only know how to kill, we’re going to keep on living our lives and trying to lift people up,’’ the president said. ‘‘We go to our stadiums, we cheer for our teams, we thrive in our cities, we run our races, as they will next week in Boston. In other words, we carry on.’’