Zimbabwean President Robert Mugabe has declared that Zimbabweans are "angry" at talks about him stepping down, as the youth wing of the ruling party says he should rule until he dies.

The battle to succeed the 92-year-old President may be decades in the making, but its outcome is far from settled. The situation is further complicated by the incumbent's refusal to publicly identify a favoured replacement, instead opting to hang on to power indefinitely, and keep his potential successors guessing.

"You just go to Zimbabwe now and ask the people whether I should stand down. They will be angry with you," Mugabe told Japanese media on Tuesday, on a five-day visit during which he secured ¥600m (US$5m) in financial assistance from the Japanese government.

During the interview, Mugabe claimed the demands for him to step down were coming from outside of Zimbabwe. "If they don't like my long stay in power they should criticise my people, I do not vote for myself into power," the head of state, who has been in power for 36 years, was reported as saying by the state-owned Herald newspaper.

The nonagenarian insisted that he would run for another term in office in the 2018 elections – health permitting. "At the moment I am the president, that's why (I am here). Do you see me as not fit? Why not contest two years later?

He added: "Two years later is no time but only God knows what will happen in two years' time, 2018, I don't know, it will depend. If I am fit enough, yes, but If I am not fit enough I will not. My people will want me to be a candidate and they have already nominated me as a candidate for 2018."

G40 Youth: 'Mugabe must rule until he dies'

Mugabe has found support in the youth wing of the ruling Zanu-PF party, who have vowed to stand by their ageing leader, claiming Mugabe must rule until he dies.

To show their support, the youth aligned to Zanu-PF's Generation 40 (G40) faction are planning a million-man march in the capital, Harare, in May to show their support.

Zimbabwe 2013 elections
Supporters of Mugabe's ZANU-PF party celebrate his election victory in Mbare on August 4, 2013. ALEXANDER JOE/AFP/Getty Images

"Our main aim on the one 'million man' march is to show the president that we are fully behind him. We want him to be our president for life and those that do not agree are free to go to ZEC and remove their name there or vote otherwise," says Zanu-PF Youth League political commissar, Innocent Hamandishe, according to NewsdzeZimbabwe.

Zanu-PF national political commissar, Saviour Kasukuwere, meanwhile, is reported as having accused a number of Zanu-PF bigwigs as eyeing the top seat.

Referring to Team Lacoste – the faction rallying behind vice president Emmerson Mnangagwa, who appeared to confirm his position as Mugabe's presumed successor –Kasukuwere said: "There is no vacancy for the presidency both in Zimbabwe and in Zanu-PF. There is only one leader and one centre of power."

War veterans 'rebellion'

This comes days after Mugabe accepted to sit down for a crunch meeting with disgruntled war veterans – who have been calling on the president to step down.

The freedom fighters are described as being the largest rebellion against Mugabe's rule, and government forces responded to a meeting in Harare last month with tear gas and water cannons.

Officially, the 7 April meeting is aimed at discussing the veterans' welfare issues, but a party member told news outlet New Zimbabwe.com last weekend that this was "nonsense", as the War Veterans Act already details the benefits that former fighters, their widows and children are entitled to.

"As he did with the civil servants' bonuses, Mugabe simply needs to instruct treasury to pay them what they are due (...) You don't need to call a national meeting including security services chiefs to discuss what is clear under the law. The fact is that Mugabe realises the scale and depth of the rebellion against his rule."

The official added: "That is why he promptly apologised for teargassing the veterans. He will use the April 7 meeting to try and buy the disgruntled veterans and the security services chiefs off."

War veterans in Zimbabwe
Zimbabwean war veterans sing revolutionary songs at a meeting at the ruling Zanu-PF. Reuters