(CNN) -- U.S. Secretary of State Hillary Clinton called Sudan a "ticking time bomb," and urged international leaders to help ensure a successful referendum process by intensifying efforts to bring the north and south together.
A January 2011 referendum will determine whether the semi-autonomous southern Sudan should declare its independence from the north.
The referendum was part of a 2005 peace agreement that ended two decades of violence between the north and oil-rich south. The conflict led to the deaths of 2 million people, many from starvation.
Sudan's upcoming referendum presents a difficult set of challenges, Clinton said .
"The situation [in the] north-south is a ticking time bomb of enormous consequence," Clinton said Wednesday. "So we are ramping up our efforts to bring the parties together, north and south, the African Union, others to focus on this referendum which has not been given the attention it needs."
Clinton said the U.S. has increased its diplomatic efforts, including increasing its presence in Juba by opening "a kind of consulate." Juba is the capital of the south.
The secretary of state called the passage of the referendum "inevitable," adding that the United States is looking beyond the vote.
At stake are Sudan's massive oil reserves, found mostly in the south, but still controlled by the government in the north.
"Simultaneously, we're trying to begin negotiations to work out some of those intractable problems. What happens to the oil revenues? And if you're in the north and all of a sudden, you think a line's going to be drawn and you're going to lose 80 percent of the oil revenues, you're not a very enthusiastic participant."
Any deals made will focus on limiting the potential of violence, according to the secretary of state.
Clinton said the north may not warm up to the idea of losing oil revenues in the south. However, she urged, making some "accommodations" with the north will help limit violence
"We've got to figure out some ways to make it worth their while to peacefully accept an independent south, and for the south to recognize that unless they want more years of warfare and no chance to build their own new state, they've got to make some accommodations with the north as well."
Omar al-Bashir is the president of Sudan, while Salva Kiir Mayardit serves as the nation's vice president and also leads southern Sudan.
However, the north-south divide is not the only concern in Sudan.
A separate deadly conflict occurred in the Darfur region, where government-backed Janjaaweed militias waging a brutal campaign against African tribes have killed hundreds of thousands. The United States and the International Criminal Court pointed the finger directly at al-Bashir, who has dismissed the allegations.
CNN's David McKenzie contributed to this report.