The Office of the President of the United States has welcomed the new peace deal belatedly signed by South Sudan's President Salva Kiir, but warned that it does not recognize a list of reservations that he made when signing the document.

"President Kiir made the right decision to sign the peace agreement," said White House spokesman Josh Earnest, as quoted by AFP in Washington. He added, "The US does not recognize any reservations or addendums to that document."

At the signing ceremony on Wednesday, Kiir repeatedly expressed reservations to the deal. His government also sought to attach a 12-page list of reservations on many key points of the deal.

"The current peace we are signing today has so many things we have to reject," President Kiir said at the ceremony.

Kiir's top general has strongly opposed the signing of the agreement and one of his cabinet ministers walked out of the signing ceremony in disgust. The president himself has also criticized the peace proposal on several occasions in the last two months before he signed it today.

File photo: US President Barack Obama and Secretary of State John Kerry, 1 November 2013 (White House/Pete Souza)