South Sudan president warns sanctions will worsen war

South Sudan President Salva Kiir has warned that proposed international sanctions will only worsen the civil war ravaging his country.

Repeated threats of sanctions by the UN Security Council, as well as the African Union and regional bloc IGAD, have been made amid fierce international criticism of Kiir and his arch-rival, rebel chief Riek Machar, for failing to end a 17-month war that has seen accusations of gross human rights abuses.

"At this time, discussion of sanctions is unproductive," the statement from the office of the president read, describing South Sudan as the "embers" of a fire that could flare up at any time.

"Sanctions will only serve to fan the flames of the current tensions. They will not speed up dialogue and compromise and they will not feed and employ the people of South Sudan."

The government launched a major assault against rebels in late April in one of its heaviest offensives yet, cutting off over 650,000 people from aid, with gunmen raping, torching towns and looting relief supplies, according to the United Nations and aid agencies.

Rebels last week launched a major counter-attack, including an assault on Malakal, the state capital of Upper Nile and the gateway to the country's last remaining major oil fields.

Kiir's spokesman, Ateny Wek Ateny, said the government was now in full control of Upper Nile's oil fields, although rebels have rejected the claim.

Fighting broke out in December 2013 when Kiir accused Machar, his former deputy, of attempting a coup, setting off a cycle of retaliatory killings across the country.

Washington's envoy to the UN Samantha Power said this week, in one of the strongest warnings yet, that the US was working with the Security Council to gather evidence for possible sanctions.

"The international community is footing the bill for President Salva Kiir's and opposition leader Riek Machar's shameful disregard for the devastating humanitarian crisis facing the people of South Sudan," she said in a statement.

The European Union and United States placed asset freezes and travel bans last year on commanders from both sides, but the sanctions have made little if any impact on the worsening war.

Over half of the country's 12 million people are in need of aid, with 2.5 million people facing severe food insecurity, according to the UN.