The Obama administration expressed alarm Tuesday about an escalation of violence between Sudan and South Sudan and called for the leaders of the two nations to meet to resolve their differences.
Secretary of State Hillary Rodham Clinton called the violence "deeply distressing" and urged Sudanese President Omar al-Bashir and South Sudan President Salva Kiir to reschedule a summit that had been scheduled for next week but was cancelled when Bashir pulled out.
"We want to see that summit held and we want to see both sides work together to end the violence," she told reporters at the State Department. "It is incumbent on the leaders of both countries to resume negotiations and the United States stands ready to assist in working out the contested issues."
She said both sides have to end the violence but that the greater responsibility lies with Sudan, which has more advanced weapons and is using them in the South Kordofan and Blue Nile regions.
"We think that the weight of responsibility rests with Khartoum because the use of heavy weaponry, bombing runs by planes and the like are certainly evidence of disproportionate force on the part of the government in Khartoum," Clinton said. "At the same time we want to see South Sudan and their allies or their partners ... similarly participate in ending the violence and working to resolve the outstanding issues."
On Capitol Hill, the Senate Foreign Relations Committee approved on a voice vote a resolution demanding that the Sudan government allow humanitarian access to the Blue Nile and South Kordofan.
"I am disappointed that renewed border clashes led President Bashir to cancel next week's summit in Juba, and encourage both sides to immediately return to negotiations," said Sen. Chris Coons, D-Del., the chairman of the Foreign Relations subcommittee on Africa.
"This is the best way to avoid further deterioration of a humanitarian crisis in the border regions, fulfill the aspirations of South Sudan as an independent nation, and chart a new path forward for Sudan," he said.
The comments, along with from the White House appealing for both sides to "exert the greatest restraint ," came after Sudan's military bombed an oil field in the new nation of South Sudan on Tuesday. That came a day after the two sides clashed in a disputed border town, prompting Bashir to cancel his planned trip to the South Sudan capital of Jube for the meeting with Kiir.
The cancellation effectively halted momentum in negotiations between the two countries on issues leftover from a 2005 peace deal that saw South Sudan separate from Sudan last July and become the world's newest nation.
Oil has been the biggest disagreement. The row prompted South Sudan to shut down its oil production in late January, depriving both countries of a critical revenue stream.
Talks were stalled until two weeks ago when the two sides reached an agreement on citizenship and border demarcation. The agreements _ meant to be signed next Tuesday _ were seen as positive steps.
But there were early signs the deal might not hold. Both countries have accused each other of supporting rebel groups on either side of the border, though both sides deny the allegations.
Associated Press writer Donna Cassata contributed to this report.