Children sing slogans against South Sudan's President Salva Kiir in an IDP (internally displaced persons) camp in the United Nations Mission In South Sudan (UNMISS) base in Juba May 6, 2014. Image Credit: REUTERS

United Nations: The United States is planning to impose sanctions on individuals on both sides of the South Sudan conflict in the coming days, US and other diplomatic sources told Reuters on Monday.

The sources, who spoke on condition of anonymity, said that the sanctions would involve a ban on travel to the United States and the freezing of any assets under US authority. People on both the rebel and government sides will be targeted, the sources added, without disclosing names.

News of an imminent US move came as Secretary of State John Kerry threatened sanctions against South Sudan rebel leader Riek Machar if he spurned peace negotiations, while government forces battled for control of the northern oil town of Bentiu.

On Monday, Kerry said his government “condemns in the strongest terms” a new offensive by South Sudanese government forces against opposition-held positions, Bloombeg reported.

“These attacks blatantly violate” a January truce, Kerry said in an e-mailed statement after the forces seized the stronghold of the country’s rebel leader and the capital of oil-rich Unity state from insurgents.

Government forces on May 4 retook Unity’s capital, Bentiu, and Nasir, the town in neighbouring Upper Nile state used as a base by former Vice President Riek Machar, army spokesman Philip Aguer said by phone on Monday from the national capital, Juba. Rebel spokesman Mabior Garang confirmed the army had recaptured the towns.

“It’s not a fragile takeover,” Aguer said. Nasir is “very crucial because that was the headquarters of Riek Machar.” The government expects attacks on the oil-producing state to cease as a result, Bloomberg cited him as saying.

Fighting erupted in the world’s newest nation on December 15 with President Salva Kiir accusing Machar of leading a coup, a charge Machar denies. Violence has left thousands of people dead and forced more than a million to flee their homes, according to the United Nations.