HARARE, Zimbabwe (AP) -- Zimbabwean President Robert Mugabe said Saturday the unity government is short-lived and he plans to regain his hold over the country he has ruled for nearly three decades.

Mugabe appeared triumphant after being re-elected to the leadership of his ZANU-PF party, which has been severally weakened after it lost its parliamentary majority in last year's contested elections.

The 85-year-old leader was forced into a power-sharing deal with former rivals after the 2008 poll, but many fear it is doomed to fail as Mugabe clings on to power.

The inclusive government has a short life of 24 months," he said. "So we must be ready for the elections and we must not be defeated like we were last year. We must win resoundingly and regain the constituents we lost.

A new election date has not been set, but many observers fear that the build up will see the return of the violence that has marred previous polls.

Joice Mujuru, a former guerrilla fighter in the bush war, retained her post of second vice president. John Nkomo was elected as the party's other vice president to replace Joseph Msika, who died this year.

Zimbabwe's ambassador to South Africa, Simon Khaya Moyo, will take over from Nkomo as party chairman.

The party has been long divided over who should eventually succeed Mugabe, but the liberation hero has thwarted any challenges to his leadership.

On Friday, Mugabe lashed out at about 10,000 delegates, saying infighting was "eating" the party and had cost them last year's election.

Election officials declared a runoff was necessary after the 2008 vote, but opposition leader Morgan Tsvangirai dropped out, citing attacks against his supporters. Mugabe was later declared the winner, but he formed the unity government in February with Tsvangirai as prime minister.

Zimbabwe is struggling to emerge from political gridlock, economic collapse and international isolation and sanctions.

Critics blame Mugabe's land reform policies for Zimbabwe's economic meltdown after he ordered the seizures of thousands of white-owned farms in 2000, disrupting the agriculture-based economy in the former regional breadbasket.

However, on Saturday, Mugabe remained characteristically defiant.

Land reform is irreversible," he said. "We took the land and we are not going to hand it to the white farmers.