Zimbabwe's president, Robert Mugabe, Saturday was declared the ruling party's candidate for the 2018 elections.

President Robert Mugabe officially closed Zimbabwe's ruling Zanu PF annual conference in Masvingo, about 300 kilometers south of Harare, after the party had unanimously endorsed him as its candidate for the 2018 elections.

Some members of Zimbabwe's ruling party have been calling on the 92-year-old leader to step down. That probably explains his plea to party members on Saturday for tolerance.

"We have agreed that there must be no conflicts and fighting. Discipline, discipline, discipline. Those in leadership must be respected," he said.

Now it remains to be seen how a 94-year-old will fare in Zimbabwe in 2018 elections. He is already struggling to walk and makes frequent trips to Malaysia for medical attention. Unconfirmed reports say the Zimbabwean leader - who has been in power since it won independence from Great Britain in 1980 - has prostate cancer.

Africa's oldest head of state, Mugabe, saying he has no immediate plans to step down, said he was not happy with some members of his ruling ZANU-PF party who are calling for him to resign.

The 92-year-old leader urged his party to unite as Zimbabwe heads toward its next elections in 2018.

His party has two factions angling to succeed the Zimbabwean leader.

Mugabe accused the factions of using social media to attack each other, saying "we must not settle our issues through Facebook and Twitter."

"There is a new culture of indiscipline in the party by some of the members who are here," Mugabe said. "They do what they want. There is even contempt and arrogance."

In the Shona language, he says there are some who say they no longer like Mugabe. He asks them: What do you want done?

It is almost taboo in ZANU-PF to discuss who will replace Mugabe, who has been at the helm of Zimbabwe since it won independence from Great Britain in 1980.

But with Zimbabwe's collapsed economy showing no signs of life, and with the president set to turn 93 in February, such talk has begun - even though the president is choosing not to hear.