UNITED NATIONS, Sept. 13 (Xinhua) -- UN Secretary-General Antonio Guterres on Thursday welcomed the signing of a new peace agreement in South Sudan, hailing it as "a positive and a significant development."

"The secretary-general commends the parties on this step forward and applauds regional and international efforts that led to the signing of the agreement," said Farhan Haq, Guterres' deputy spokesman, in a statement.

The secretary-general calls on the signatories of the agreement to fully and inclusively implement the agreement both in letter and spirit, so that the people of South Sudan can finally receive the peace dividend they deserve, said the statement.

It is imperative that all parties immediately cease hostilities across South Sudan, it added.

The road ahead remains challenging and the international community must remain seized of the situation in South Sudan, said the statement.

The United Nations stands ready to assist the parties in implementing the peace agreement that was signed on Wednesday, it said.

Shortly after its independence from Sudan in 2011, South Sudan plunged into civil war. Up to 300,000 people are estimated to have been killed since late 2013.