PRIME Minister Julia Gillard said Australia had worked closely with President Obama and his administration over the past four years, adding "I look forward to continuing this friendship".
The government is relieved at the status quo result as it heads into its own election year; a Romney presidency could have created new international uncertainty.
Ms Gillard said that US leadership "remains vital to meeting global challenges: international financial stability and global economic growth, peace and security, and the impacts of our changing climate". She said the two countries would work together on the United Nations Security Council in 2013-14 during Australia's term as a non-permanent member.
"Australia and the United States are unique partners," she said.
In a briefer congratulatory statement, Tony Abbott said:
"The United States is Australia's largest and most important ally and Australia can look forward to a continuation of the best possible relations."