The president of South Sudan has told US Secretary of State John Kerry that he intends to sign a peace accord meant to end the civil war in that country, the State Department said Wednesday.

On Monday, President Salva Kiir initialed part of the power-sharing deal, but said he would wait until early September before finalizing it.

Washington criticized Kiir at the time for what it called a failure of leadership in acting to end the two-year war between government forces and rebels that has killed tens of thousands in the world's youngest country.

Kerry spoke with Kiir by telephone Wednesday, State Department spokesman John Kirby said.

"President Kiir assured the secretary that he has every intention of signing the peace agreement. He said he needed a couple more days of consultations but he made it very clear that it was his intention to sign," Kirby said.

The head of the rebel group, Riek Machar, signed the peace accord Monday, and on Tuesday the US and Britain pushed for UN sanctions against Kiir if he fails to sign it.

Both the government and rebels accused the other side of launching new attacks Wednesday.