WASHINGTON -- President Obama said Sunday the world is watching as voters in southern Sudan go to the polls in a weeklong referendum that's expected to split the troubled African nation into two parts and create the world's newest country.
Writing in The New York Times, Obama said that not every generation has the opportunity to "turn the page on the past and write a new chapter in history."
"Yet today, after 50 years of civil wars that have killed 2 million people and turned millions more into refugees, this is the opportunity before the people of southern Sudan," he said.
The south, which is mostly Christian, is expected to secede from the mainly Muslim north, dividing Africa's largest country in two.
Obama said the vote and the action of the leaders of Sudan will help determine whether Sudan will "move toward peace and prosperity, or slide backward into bloodshed."
The referendum, he said, will have consequences not only for Sudan, but also for sub-Saharan Africa and the world.
Omar al-Bashir, the president of Sudan who's facing charges for alleged genocide and war crimes in the western Darfur region, has vowed to honor the outcome of the vote and let go of the oil-rich south. His government tried for years to derail the referendum now taking place under massive international scrutiny.
"Now, the world is watching, united in its determination to make sure that all parties in Sudan live up to their obligations," Obama said. "As the referendum proceeds, voters must be allowed access to polling stations; they must be able to cast their ballots free from intimidation and coercion."
The south is one of the poorest regions in the world and the people who live there have long accused the northern Arab-dominated government of taking their oil revenues and not putting anything back.
"A successful vote will be cause for celebration and an inspiring step forward in Africa's long journey toward democracy and justice," Obama said.
But, he cautioned, lasting peace in Sudan will demand far more than a credible referendum.
He said the peace pact agreed to in 2005 must be fully implemented and that border disputes need to be peacefully resolved.
Obama also said there can be no lasting peace until the situation in Darfur is resolved. He said that the government of Sudan must live up to its obligations and stop the attacks on civilians in the region.
"The United States," Obama said, "will not abandon the people of Darfur."