South Sudan rebel warns president of more fighting if he stays on

JUBA, July 8 (Reuters) - South Sudan's rebel leader warned on Wednesday of renewed fighting, saying President Salva Kiir's new three-year mandate was illegal and the people had the right to "rise up and overthrow his regime" if he stayed on.

Riek Machar made his statement in the capital of neighbouring Kenya as South Sudan's parliament speaker formally extended Kiir's term for three more years, as approved by lawmakers in a March vote.

Rebels say parliament did not have the right to take such action, in a nation that has been mired in conflict since December 2013.

"Should President Kiir remain adamant and refuse to hand over power to the people, then the citizens have every right to rise up and overthrow his regime," Machar said, adding Kiir's term ended from midnight on July 8.

"This is not an elected president. This is a coup leader," he said.

Fighting between forces loyal to Kiir and rebels allied with Machar plunged South Sudan, the world's youngest nation, into a civil war in December 2013. South Sudan will mark four years of independence from Sudan on Thursday.

At an event in the capital Juba on Wednesday, Kiir said the continued fighting was destroying the country's economy.

"You cannot see any country developing while fighting internal insurgence or fighting an external enemy, because whatever you have in your economy you have to give it to the fighting forces," he said.

"It is not me alone who will stop the war but it is all of us in South Sudan that should work to stop the war."

But more than a year and a half of on-off talks in Ethiopia have failed to end fighting that has killed thousands of people and driven more than 2.2 million from their homes, many of them fleeing to neighbouring states, including Kenya.

About 8 million people, or two-thirds of the total population, face food shortages. More than 12,000 children have been recruited by armed groups to serve as soldiers, the United Nations estimates.

Machar called the humanitarian crisis "appalling," but said South Sudanese would still rejoice as they marked their independence.

"We love it. We cherish it. It's governance that failed," he said. "Things will correct themselves. We shall we a proud nation in this part of Africa." (Reporting by Denis Dumo in Juba and Edith Honan in Nairobi; Writing by Edmund Blair)