President Obama warned Libyan leader Moammar Gadhafi and his aides today that they will be held accountable for war crimes, and that the U.S. and NATO are considering possible responses that include potential military action.

"We've got NATO as we speak consulting in Brussels around a wide range of potential options, including potential military options, in response to the violence that continues to take place inside of Libya," Obama told reporters after a meeting with Australian Prime Minister Julia Gillard.

Obama did not specify any of those options -- such as the much-discussed proposal to establish a no-fly zone over Libya -- but said he wanted "to send a very clear message to those who are around Col. 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 there," Obama said.

Obama refused to answer repeated questions about the impact of oil prices that have risen in recent days due to the unrest in Libya and throughout the Middle East.

In prepared remarks, Obama said he and Gillard share "a very firm conviction that the violence that's been taking place and perpetrated by the government in Libya is unacceptable." He thanked Australia for joining the U.S. and others "in imposing swift and firm sanctions, comprehensive sanctions, against the government."

Obama also announced an additional $15 million "that will be provided to aid organizations that are already on the ground."

Obama also said of Libya: