A Sudan People's Liberation Army – North (SPLA-N) soldier stands on the front line at Mufalu, South Kordofan state on April 6, 2012.
The Sudanese army has said its troops have started an operation to liberate the occupied town of Heglig in the oil-rich southern region, which South Sudanese forces captured earlier this week.
"Now we are moving towards Heglig town" and are "close," army spokesman Sawarmi Khaled Saad said in a statement issued on Friday, AFP reported.
He added that the occupation of Heglig would end in the coming hours.
The army spokesman also said that South Sudan had tried but failed to take over “all of South Kordofan state."
Sudanese President Omar al-Bashir has accused South Sudan of implementing plans dictated by foreign powers. Bashir also said the South has chosen the path of war instead of dialogue.
Tension between the two countries has escalated in recent days. Khartoum has also pulled out of crisis talks led by the African Union to resolve a series of issues including an oil dispute, border demarcation, and citizenship problems.
South Sudan became independent on July 9, 2011 after decades of conflict with the north in which over 1.5 million people died. The new oil-rich nation is one of the least developed countries in the world, where one in seven children dies before the age of five.
A historic peace agreement between North and South Sudan signed in 2005 paved the way for an independence referendum in January 2011, in which southerners voted almost unanimously to secede.