Alexander Mercurio, 18, was arrested for attempting to provide material support to ISIS, police said. The FBI thwarted his plans to use knives, firearms and fire for attacks, authorities said.

The Justice Department announced the arrest of a man they say planned to carry out attacks on churches over the weekend after pledging support to the terror group ISIS.

ISIS has claimed responsibility for the attack in Moscow that killed at least 144.

ABC News’ Martha Raddatz interviews former CENTCOM Commander Gen. Frank McKenzie on “This Week.”

ABC News’ Martha Raddatz reports on the resurgence of the militants on “This Week.”

ISIS has a "strong desire" to attack the U.S. and other foreign powers -- a threat that is only growing -- retired Gen. Frank McKenzie warned on Sunday

ABC News’ Martha Raddatz breaks down the latest in the Moscow concert hall attack on “This Week.”

A Colorado teenager has been charged with providing material support to ISIS.

Hundreds of Yazidi-Americans filed a civil lawsuit Friday against French conglomerate Lafarge S.A. for conspiring to provide material support to the Islamic State.

A British man accused of being one of the four ISIS "Beatles" who beat and killed U.S. hostages in Syria was faced down in federal court by two of their victims' mothers.

El Shafee Elsheikh faces a life sentence following his conviction by a federal jury.

U.S. officials say the drones that killed terrorist leader Usamah al-Muhajir near Aleppo, Syria were harassed by Russian aircraft on the same day.

The U.S. military said Saturday that U.S. drones "harassed" by Russian jets on Friday later carried out airstrike on a top ISIS leader

The Supreme Court on Thursday sided with social media giants in a case brought by families of victims in a terrorist attack in Turkey.

Over 150 Afghans and 13 U.S. service members were killed in the 2021 attack.

U.S. forces conducted a raid against ISIS militants in northwest Syria on Monday, according to U.S. Central Command.

Four U.S. service members were wounded by an explosion during a helicopter raid in northeast Syria Thursday night.

Four U.S. troops and a service dog were wounded in Syria during an operation that resulted in the death of a senior ISIS leader, according to officials.

Four American special operations soldiers and a service dog were wounded while a senior ISIS leader was killed.

A former Brooklyn man, who became a sniper and weapons instructor for ISIS, was convicted Tuesday of providing material support to terrorism and other charges.

Bilal al-Sudani, a top leader and organizer with the Islamic State, was killed in a risky U.S. military ground raid in northern Somalia, official said

The dramatic raid in Africa by an elite American special operations team killed senior ISIS leader Bilal Al Sudani and at least 10 other militants, according to the Pentagon.

Bilal al-Sudani was among 10 ISIS fighters killed in a firefight that ensued as U.S. special operations forces carried out a ground raid targeting a cave complex, officials said.

U.S. Central Command announced a helicopter raid killed two members of the Islamic State terrorist group in Syria Sunday morning.

A U.S. helicopter raid killed two members of ISIS in Syria early Sunday morning local time, U.S. Central Command announced

Allison Fluke-Ekren, 42, pleaded guilty in June to expressing interest in carrying out terrorist attacks in the United States in support of ISIS on six separate occasions between 2014 and 2017.

A Kansas mother who was convicted of leading an ISIS battalion was sentenced to 20 years in prison.

LaFarge agreed to pay $777 million in fines and conceded it knowingly and intentionally conspired to support ISIS.

A company paid ISIS in order to keep its cement plant in Syria operable.

El Shafee Elsheikh was sentenced to 8 life terms for kidnapping and murdering journalist James Foley as well as the detention and murders of three others.

The Pentagon said there were no civilian casualties and another senior ISIS official was wounded in the drone strike in northwest Syria.

A U.S. military raid in northwest Syria has led to the capture of a top ISIS leader, according to a U.S.-led anti-ISIS coalition.

A rare U.S. military ground raid in northwestern Syria has captured a top ISIS leader, according to the U.S.-led anti-ISIS coalition.

The U.S. military conducted a ground raid in northwestern Syria that captured a top ISIS leader, the U.S. military said Wednesday.

The U.S. military conducted a ground raid in northwestern Syria that captured a top ISIS leader, the U.S. military said Wednesday.

Allison Fluke-Ekren, 42, who was captured in Syria, pleaded guilty to terrorism charges in a Virginia courtroom on Tuesday.

A Kansas mother accused of leading an ISIS battalion pleaded guilty, federal prosecutors in northern Virginia announced Tuesday.

President Joe Biden announced Thursday that a U.S. raid in Syria killed the leader of terrorist group ISIS, known as Haji Abdullah.

President Biden announced that the leader of ISIS was killed during the daring raid carried out by the U.S. special forces.

Administration officials gave a behind-the-scenes account of President Joe Biden's role in the U.S. raid that left the leader of ISIS dead.

The Pentagon called the overnight counterterrorism operation a success and said the civilian deaths at the site were not caused by the actions of the American military.

Plus, a D.C. principal explains the secret behind getting kids vaccinated and the Washington Commanders hire the NFL’s first Black woman as an assistant coach.

President Joe Biden said U.S. special forces detonated an explosive that killed an ISIS leader and members of his family, adding that the U.S did everything possible to limit civilian casualties.

Plus, Russia has accused the U.S. of fueling military tensions as the Ukraine crisis escalates, and the FBI has launched a hate crime investigation into bomb threats against more than a dozen HBCUs.

ABC News Chief Global Affairs Correspondent Martha Raddatz gives an update on the overnight U.S. forces raid.

Plus, Russia reacts to President Joe Biden’s decision to send 3,000 troops to Eastern Europe, and a former college tennis coach speaks out after his involvement in the “Varsity Blues” scandal.

President Joe Biden said Thursday morning a U.S. Special Forces operation in Syria left the leader of ISIS dead.

Elizabeth Neumann, a former homeland security official in the Trump administration, discusses the importance of this operation and the concern over possible retaliation.

The operation was months in planning, and initiated on his orders, the president said.

ABC News’ chief global affairs correspondent Martha Raddatz reports on the latest details of the aftermath of a counterterrorism mission conducted in Syria.