In unveiling the "It's On Us" campaign aimed at preventing attacks on college campuses, President Obama said such violence is "an affront to our basic humanity."
Petro Poroshenko called Russia's annexation of Crimea a "cynical act of treachery." He is in the U.S. meeting with President Obama and others to lobby for increased aid to fight insurgents.
The president said U.S. airstrikes, combined with military expertise, would be more effective in defeating the group that calls itself the Islamic State.
The expected vote on whether to authorize the Obama administration's plan to arm and train moderate fighters comes as the president meets with military officials at U.S. Central Command.
The U.S. military plans to establish a medical base in Liberia to help stop the Ebola epidemic. It will build 1,700 new treatment beds and train up to 500 health care workers every week.
President Obama says the strategy the U.S. would pursue against the Islamic State would be similar to how it targets al-Qaida affiliates in Yemen and Somalia. But both countries are deeply unstable.
The president has opted for an open-ended air campaign to fight the Islamic State. A look at what it will take to make the plan work and the risks that could cause it to fail.