FILE PHOTO: South Sudan President Salva Kiir attends a South Sudan peace meeting as part of talks to negotiate an end to a civil war that broke out in 2013, in Khartoum, Sudan June 25, 2018. REUTERS/Mohamed Nureldin Abdallah/File Photo

(Reuters) - The United States on Thursday condemned a bill proposed by South Sudan’s government that would extend President Salva Kiir’s term for three years.

“The draft bill undermines ongoing peace talks with opposition groups and civil society,” a State Department official, who spoke on condition anonymity, said.

Backed by the United States, South Sudan gained independence from Sudan in 2011.

Fighting broke out two years later over a political disagreement between Kiir and his former vice president Riek Machar. Tens of thousands of people have since been killed and over three million forced to flee their homes.

Kiir and Machar met last week and agreed on a new peace deal. It included a ceasefire, which took effect on Saturday. It was violated that day when government and rebel forces attacked each other’s positions.

A spokesperson for the rebel group, SPLM-IO, said on Tuesday that the government was proposing an “illegal procedure” in attempting to extend Kiir’s presidential term.

The proposed bill would amend South Sudan’s constitution to extend Kiir’s presidency through 2021, lawmakers told Reuters on Tuesday.

The State Department official said that South Sudan should work quickly to reach a peace agreement that leads to free and fair elections.