This morning, the US ambassador to NATO said the alliance had started 24-hour air surveillance of Libya using AWACS reconnaissance aircraft.
Mr Obama described the violence against the Libyan people as unacceptable and said NATO was considering military options in response.
NATO defence ministers are expected to discuss the growing conflict and calls for a no-fly zone later this week.
Speaking in Saudi Arabia, Mr Rudd said the African Union and the Arab League would be important in shaping a consensus within the UN Security Council.
Mr Rudd says Australia has sent emergency aid to the Red Cross, the UNHCR and other agencies to help Libyans fleeing into Egypt and Tunisia to escape the violence.
The United Nations has now appointed a special envoy to Libya to deal with the humanitarian fallout from the conflict.
It has also announced a $160 million relief fund to provide shelter and food for the tens of thousands of refugees fleeing the country.
In Abu Dhabi, Gulf Arab states issued a statement voicing their support for imposing a no-fly zone over Libya.
“The Gulf Cooperation Council demands that the UN Security Council take all necessary measures to protect civilians, including enforcing a no-fly zone over Libya,” the six-nation bloc’s statement said.