Obama, speaking at the UN, asked the world to join together to fight the militants and vowed to keep up military pressure against them.
The secretary of state says the U.S. would pledge $40 million for Syria's opposition groups, part of which will be to boost their ability to govern.
White House officials want to clarify legal justifications for the airstrikes in Iraq and Syria, but definitive answers are hard to come by.
The cost to the U.S. military of bombing ISIS may reach as high as $10 billion.
The resolution requires states to combat terrorism domestically and prevent their citizens from leaving to fight for foreign terrorist groups.
"Who do you think President Obama could appoint at this very day, given the boundaries that we have?" Ginsburg said.
"Russian aggression in Europe recalls the days when large nations trampled small ones in pursuit of territorial ambition,” Obama said
At the U.N. General Assembly on Wednesday, Obama addressed ISIS, saying that "the only language these terrorist groups understand is force."
U.S. Secretary of State John Kerry suggested the Iraqi capital might have come under ISIS control if not for U.S. airstrikes.
As countries adopt strategies to reduce greenhouse gas emissions, demand for the dirtiest fossil fuels could drop, Capital Economics says.
A federal judge sentenced Dinesh D'Souza to a community confinement center for violating campaign finance law.
Watch President Obama and other world leaders address the United Nations.
"Islamic State continue to ignore our pleas to open dialogue,” Barbara Henning, wife of the British hostage, reportedly said.
One of the key leaders of to al-Nusra Front has been killed in airstrikes in Syria, the group said in a statement.
Monday's "unprecedented" joint effort reveals the anxiety that ISIS has caused in the Middle East for majority-Sunni countries.
At the U.N. summit, U.S. and Chinese leaders both indicated their countries would set ambitious emissions reduction targets ... eventually.
U.S. Ambassador Samantha Power cited Article 51 of the U.N. Charter to justify the airstrikes.
Militants already had moved their families to suburban locations and reportedly only went out under cover of darkness.
Without having to worry about ISIS, the Syrian regime can now turn its attention to other rebel groups threatening Bashar Assad's forces.
Six weeks of U.S. airstrikes in Iraq have failed to wipe out Islamic State group militants. What does that say about the Syria campaign?
The rules are intended to limit American companies from reaping tax benefits by merging with foreign companies.
House Speaker John Boehner said the airstrikes "must be part of a larger effort" to destroy ISIS.