Sudan is threatening to close its border with South Sudan and deport more than 300,000 South Sudanese students on grounds that the South is supporting rebels fighting the government of President Omar al-Bashir.
Ibrahim Mohamud Hamid, a senior assistant to Bashir, aired the accusation and warnings on Thursday.
South Sudan’s Foreign Minister Barnaba Marial Benjamin denied his government is supporting rebels of the Sudan People’s Liberation Army, or SPLA North, who are fighting the Sudanese government in Southern Kordofan and Blue Nile states.
Marial, speaking to VOA's South Sudan in Focus program, said his country is working to bring peace to Southern Kordofan and Blue Nile.
"President Salva (Kiir) and the government are fully committed to see that there is peace in Sudan and peace in South Sudan," he said. "And the president is very clear that we will not support any armed insurgency against the Republic of Sudan."
Sudan and South Sudan signed a cooperation agreement four years ago to stop supporting rebels in each other’s territory, to promote trade and to create two viable states.
But the border was closed until earlier this year, when Sudanese President Bashir ordered it open to help the South cope with its ongoing economic crisis, caused by the country's civil war.
Rabi Adelati, a senior member of Sudan’s ruling National Congress Party, backed Hamid's accusation and said Juba’s support to Sudanese rebels is creating tension between the two countries.
"This will really affect security, affect peace and affect the [South Sudan] government," Adelati said. "As you know the situation in South Sudan is vulnerable.... And I think that if the stance of (South Sudan’s) government [is] to cooperate with SPLM-North, this will definitely result in negative impact on the two countries," he said.
Adelati said it is time for the Sudanese government to tighten security along its borders with South Sudan.
South Sudan's Marial said his government can end the conflict in Southern Kordofan and Blue Nile states if given a chance to do so.
‘’Some of these problems can actually be resolved by enhancing our trade, encouraging the movement of the people, educating our children together," he said.
"’We have that relationship, whether it is a social relationship, whether we were in one country before. This can be used for the advantage of South Sudan putting pressure on our brothers and sisters in the Sudan so that they can reach a peaceful agreement that will make our region a viable region, politically, economically and even socially and culturally,’’ he added.
Sudan and South Sudan have struggled to maintain good relations since the South broke away and won independence in 2011.
South Sudan’s foreign minister expressed concern last year about reports that Sudanese President Bashir promised military support to rebel leader Riek Machar to forcefully take power in the world’s youngest nation.
VOA fellow Nadia Taha contributed to this report.