Obama increases humanitarian aid to Libya

President Barack Obama authorized an additional $15 million in humanitarian aid to Libya Monday as government forces there stepped up their crackdown on opposition forces.

Speaking in the Oval Office, Obama warned that the U.S. and its NATO allies are still considering military options to stop what he called "unacceptable" violence perpetrated by supporters of Libyan leader Moammar Gadhafi. Libyan warplanes launched multiple airstrikes Monday on opposition fighters in the second day of a harsh government crackdown to thwart rebels advancing on Gadhafi's stronghold in Tripoli.

"I want to send a very clear message to those who are around Colonel Gadhafi. It is their choice to make how they operate moving forward. And they will be held accountable for whatever violence continues to take place," Obama said.

U.S. sent an initial $10 million in humanitarian aid to Libya last month. The U.S. and United Nations have imposed sanctions on Gadhafi's regime, and U.S. military forces have also moved closer to Libya's shores to back up demands that Gadhafi step down.

Hundreds if not thousands of people have died since Libya's uprising began, although tight restrictions on media make it nearly impossible to get an accurate tally. More than 200,000 people have fled the country, most of them foreign workers, creating a humanitarian crisis across the border with Tunisia - another North African country in turmoil after an uprising in January that ousted its longtime leader.

Obama spoke alongside Australian Prime Minister Julia Gillard, who is in Washington for meetings.