A UK envoy has asked South Sudanese citizens to hold their leaders accountable for their promises.

The UK's special envoy for South Sudan, Bob Fairweather, said while President Salva Kiir and his former rival Riek Machar had promised the international community peace, only citizens would ensure no conflict occurs.

Mr Fairweather said the country had seen "much suffering due to conflict-related abuses, famine, flooding and diseases" during the first 10 years of independence.

"Sadly, as the 10 years moved forward, there were far too many mistakes made, there were too many missed steps. What is important I think is that the leaders should learn from those mistakes and take the country forward and do what should have been done in the first 10 years," he said.

The envoy was among other diplomats who attended South Sudan's tenth independence celebrations on Friday.

In his state of the nation address during the event, President Kiir pledged that he "will not return the country to war again".