Zimbabwe's President Robert Mugabe defied calls to quit Sunday, saying he will preside over a ruling party congress in December in an announcement that could trigger impeachment proceedings this week and more protests demanding his ouster.

In a televised address, the 93-year-old Mugabe acknowledged what he said were "a whole range of concerns" of Zimbabweans about the chaotic state of the government and the economy, but he stopped short of what many people in the southern African nation were hoping for — a statement that he was resigning after nearly four decades in power.

The once-formidable Mugabe is now a virtually powerless, isolated figure, making his continued incumbency all the more unusual and extending Zimbabwe's political limbo. He is largely confined to his private home by the military. The ruling party has fired him from his leadership post, and huge crowds poured into the streets of Harare, the capital, on Saturday to demand that he leave office.

Yet the president sought to project authority in his speech, which he delivered after shaking hands with security force commanders, one of whom leaned over a couple of times to help Mugabe find his place on the page he was reading.

The Central Committee of the ruling ZANU-PF party voted to dismiss Mugabe as party leader at a meeting earlier Sunday and said impeachment proceedings would begin if he does not resign by noon Monday. Mugabe made no reference to the party moves against him, instead saying he would play a leading role in a party congress planned for Dec. 12 through 17.

Zimbabwe's Robert Mugabe remained defiant during a lengthy address, refusing to resign as president amid ongoing political turmoil in his country 5:59

"The congress is due in a few weeks from now," Mugabe said. "I will preside over its processes, which must not be prepossessed by any acts calculated to undermine it or compromise the outcomes in the eyes of the public."

Officials close to the talks between Mugabe and the military had said Mugabe was resigning.

Mugabe has discussed his possible resignation on two occasions with military commanders after they effectively took over the country on Tuesday. The commanders were troubled by his firing of his longtime deputy and the positioning of unpopular first lady Grace Mugabe to succeed him. He referred to the military's concerns about the state of Zimbabwe, where the economy has deteriorated amid factional battles within the ruling party.

"Whatever the pros and cons of the way they went about registering those concerns, I, as the president of Zimbabwe, as their commander in chief, do acknowledge the issues they have drawn my attention to, and do believe that these were raised in the spirit of honesty and out of deep and patriotic concern for the stability of our nation and for the welfare of our people," Mugabe said.

'A wicked cabal'

The deputy whom Mugabe fired, former Vice President Emmerson Mnangagwa, is positioned to become Zimbabwe's next leader after the party committee made him its nominee to take over from Mugabe, who has ruled since independence from white minority rule in 1980.

Committee members stood, cheered and sang after Mugabe was removed from his post as party leader. Meeting chair Obert Mpofu referred to him as "outgoing president" and called it a "sad day" for Mugabe after his decades in power.

"He has been our leader for a long time, and we have all learned a great deal from him," Mpofu said. But Mugabe, he said, "surrounded himself with a wicked cabal."

'The speech was just surprising. It is not in line with what we expected. We had understood that his resignation was coming to avoid the embarrassment of impeachment.' - Lovemore Matuke, ZANU-PF party whip

The chief whip of Zimbabwe's ruling party ZANU-PF said, "I don't see us failing to proceed with the impeachment."

"The Central Committee decision stands until I am advised otherwise," said Lovemore Matuke.

Matuke added that "the speech was just surprising. It is not in line with what we expected. We had understood that his resignation was coming to avoid the embarrassment of impeachment. The army is taking its own route, and as politicians we are taking our own route, but the ultimate goal is to make sure he goes, which he should have done tonight."

A member of the Zimbabwe's defence forces watches as Mugabe delivers his speech. (Associated Press)

Mugabe's speech did note the political turmoil that led to his military house arrest and expulsion as ruling party leader.

"From tonight … the nation at all levels gets refocused," Mugabe said.

He also said "failures of the past" may have triggered anger "in some quarters, which he calls "quite understandable."

He also said that "intergenerational conflict must be resolved," a reference to his apparent positioning of his unpopular 52-year-old wife to succeed him. Mugabe had been backed by fellow veterans of the country's liberation war, until they turned against him.

A rivalry between Emmerson Mnangagwa, seen here, and Robert Mugabe's wife, Grace, was behind the decision to fire him on Nov. 1, say political observers. (Tsvangirayi Mukwazhi/Associated Press)

Mugabe has been under house arrest since the military moved in Tuesday, angered by his firing of his longtime deputy and the positioning of unpopular first lady Grace Mugabe to succeed him.

Mugabe tried to buy time in negotiations with the military on a dignified exit but quickly found himself isolated.

Free falling. Many <a href="https://twitter.com/hashtag/Zimbabweans?src=hash&ref_src=twsrc%5Etfw">#Zimbabweans</a> at church today praying for <a href="https://twitter.com/hashtag/Mugabe?src=hash&ref_src=twsrc%5Etfw">#Mugabe</a> to go and a better future once he goes. <a href="https://twitter.com/hashtag/CBC?src=hash&ref_src=twsrc%5Etfw">#CBC</a> <a href="https://t.co/nMDG98esmH">pic.twitter.com/nMDG98esmH</a> —@mevansCBC

Tens of thousands of people poured into the streets of the capital Saturday to demand that Mugabe, one of Africa's last remaining liberation leaders, step aside after overseeing the once-prosperous country's economic collapse.

The party meeting Sunday replaced Mugabe as party chief with Mnangagwa and recalled the first lady as head of the women's league, in decisions set to be ratified at the party congress next month. The committee accused the first lady of "preaching hate, divisiveness and assuming roles and powers not delegated to the office."

Zimbabwean officials never revealed details of Mugabe's talks with the military, but the military appeared to favour a voluntary resignation to maintain a veneer of legality in the political transition. Mugabe, in turn, has likely used whatever leverage he has left to try to preserve his legacy or even protect himself and his family from possible prosecution.

Mugabe, right, meets with Defence Forces Generals in Harare at State House , Sunday. Members of the ruling ZANU PF Central committee fired Mugabe as chief and replaced him with dismissed Deputy-President Emmerson Mnangagwa on Sunday. (The Associated Press)

'Playing games with the people of Zimbabwe'

Zimbabweans say they feel profoundly disappointed that Mugabe is resisting pressure to step aside.

Victor Matemadanda, secretary general of the country's war veterans association, said he feels betrayed.

"He is playing games with the people of Zimbabwe. He agrees to go and then plays games with us like that at the last minute," said Matemadanda.

Matemadanda says the war veterans will again rally the people to protest, and "this time the army will let him face the people … The army will now choose between shooting the people or protecting Mugabe."

Grace Mugabe was reported to have been placed under house arrest in the capital, Harare, last Wednesday, along with her husband..

Without the military's intervention last week, many observers say she likely would have replaced Mnangagwa as vice president and been in a position to succeed her husband.

Mugabe and his wife, Grace, attend his birthday celebrations in Masvingo on Feb. 27, 2016. (Tsvangirayi Mukwazhi/Associated Press)

Innocent Gonese with the MDC-T party said they had been in discussions with the ruling ZANU-PF party to act jointly.

"If Mugabe is not gone by Tuesday, then as sure as the sun rises from the east, impeachment process will kick in," Gonese said.

Soldiers stand guard on armoured vehicles on the streets of Harare on Sunday, a day after demonstrators took to the streets, shouting anti-Mugabe slogans. (Philimon Bulawayo/Reuters)

Earlier Sunday, Chris Mutsvangwa, head of the country's liberation war veterans, said he was concerned that the military could end up opening fire to protect Mugabe from protesters. He vowed to "bring back the crowd" if the president didn't step aside.

"We would expect that Mugabe would not have the prospect of the military shooting at people, trying to defend him," Mutsvangwa said. "The choice is his."