The government of South Sudan has warned that the imposition of any US-backed sanctions would be counter-productive and harm the peace process.
Foreign Minister Barnaba Marial Benjamin said that sanctions would be a burden on the people.
The US has warned that an arms embargo and other punitive measures are possible if the two sides in South Sudan’s conflict cannot agree a deal.
Talks between the government and rebels are taking place in Ethiopia.
They have until Thursday to make an agreement.
Limited sanctions on South Sudan were imposed by the UN Security Council on Tuesday.
“Those who frustrate peace must begin to pay the price,” US Ambassador Samantha Power said.
But Mr Benjamin said sanctions would “not only hinder the peace process but will inherently be felt by our countrymen and women down to the very basic level”.
“We need to remove obstacles obstructing peace not create new ones,” he said in a statement.
A resolution unanimously agreed by the Security Council does not specifically name South Sudan President Salva Kiir or rebel leader Riek Machar as possible targets for the sanctions.