Two Syrian activist groups with ties to the country's opposition also offered opposing claims about the Islamic State militant group leader's death.
Despite being largely defeated in its former Iraqi stronghold of Mosul, the Islamic State militant group is still gaining territory amid new clashes.
The Islamic State militant group killed an activist from California, a U.S. Army veteran from New York and another YPG volunteer from the U.K.
U.S. allies and enemies have praised Iraq for defeating the Islamic State militant group in Mosul, highlighting the complex nature of battling ISIS.
An Iraqi military spokesman cited by local TV said the militants' defense lines were collapsing.
Facing near-total defeat in its former stronghold of Mosul, the Islamic State militant group has launched a new, deadly offensive in Iraq.
The U.S. and Russia have taken leading, often opposing, roles in world affairs, but recent events in Syria and North Korea may invite more cooperation.
Inside efforts to rehabilitate children exposed to the militant group's extreme ideology of violence against non-believers.
So much for that "secret plan" Trump promised voters along the campaign trail to crush ISIS.
Russian fighters successfully targeted Islamic State militant group positions in Syria with Moscow’s newest Kh-101 long-range cruise missiles.
A representative to one of Iran's most elite fighting forces has confirmed the death of Islamic State militant group leader Abu Bakr al-Baghdadi
President Donald Trump has changed course a number of times on Syria, but recent events pit him directly against Russia and Iran.
What was Trump’s one-sided Twitter spat with the London mayor all about?
In a departure from previous French policy, President Emmanuel Macron endorsed Russia and Syria’s war against ISIS.
Russia severed a military hotline with the U.S. and has said it will turn its air defenses on any U.S. plane that crosses battle lines in Syria.
Tora Bora, an underground complex of fortified caves that once protected Al-Qaeda chief Osama bin Laden, is now in the hands of the Islamic State militant group.
The Russia-backed Syrian military and its allies entered ISIS-held Raqqa, where U.S.-backed forces are battling the jihadis.
Deputy Chief of Staff of Iranian Armed Forces Major General Mostafa Izadi said Tehran has evidence of the U.S.'s "direct support" for the Islamic State militant group.
Russian Foreign Minister Sergei Lavrov told Secretary of State Rex Tillerson that the U.S. must stop attacking pro-Syrian government forces fighting ISIS.
Christina Ezzo Abada was only 3 when militants took her from her family.