(CNN) -- U.S. President Barack Obama urged Sudan and South Sudan to resolve their outstanding issues through dialogue and avoid a return to war amid soaring tensions between the neighboring nations.
Clashes have escalated between Sudan and South Sudan in recent days following Sudan airstrikes targeting the South and the latter seizing the disputed oil-rich region of Heglig.
South Sudan said Saturday that its troops have left the region, but maintained its claim that Heglig is its territory.
Sudan troops are now in control of the region, but if they continue with attacks, South Sudan will retake it, said Riek Machar Teny Dhurgon, the South Sudanese vice president.
Both nations have a choice to avoid a return to war, Obama said in a videotape message to citizens of both nations .
"Sudan needs to halt all military actions, including aerial bombardments; give aid workers unfettered access to people in need; and end support for armed groups," Obama said late Friday. "Similarly, South Sudan must end its support for armed groups inside Sudan and cease its military actions across the border."
Obama's appeal joins an international call, including United Nations chief Ban Ki-moon, for the two nations to end their fighting. It comes after Sudan said Friday its forces drove out South Sudanese troops from Heglig.
Heglig is on the border created last year when the two countries split.
Sudanese President Omar al-Bashir had vowed to "never give up" the disputed region, which his nation also claims.
Oil facilities in the region accounted for close to half of Sudan's entire production of about 115,000 barrels of oil daily before wells were shut down due to the conflict.
South Sudan's seizure of the region and the resulting border clashes raised fear among the international community of renewed full-scale war. The two sides fought a civil war for two decades that led to about 2 million deaths.
Tensions run deep between both nations.
South Sudan split from the government in the north in July, officially breaking Africa's largest nation into two, the result of a referendum last year overwhelmingly approved by voters.
The referendum was part of a 2005 peace deal that ended the civil war that pitted a government dominated by Arab Muslims in the north against black Christians and animists in the south.
When they separated, South Sudan acquired three quarters of Sudan's oil reserves. The two countries have been locked in negotiations about how much the landlocked South Sudan should pay to use a pipeline and processing facilities in the north.
Other outstanding issues remain since secession, including the status of citizens of both countries who find themselves living on either side of the world's newest international border.
The fate of disputed border areas are also a point of contention.
Journalist Jared Ferrie and Alan Boswell contributed to this report.