His comments came a day after Bush described the governments of Belarus, Syria, Iran and North Korea as "brutal regimes", and criticised Mugabe's government as "tyrannical".
"[Bush] kills in Iraq. He kills in Afghanistan. And this is supposed to be our master on human rights?"
Robert Mugabe, Zimbabwe president
"His hands drip with innocent blood of many nationalities," Mugabe said in a typically fiery speech in New York. "He kills in Iraq; he kills in Afghanistan. And this is supposed to be our master on human rights?"
Mugabe, blamed for causing food shortages, soaring unemployment and hyperinflation in his country of 6,500 per cent, has accused Western countries of sabotaging the economy.
He said the US was "primarily responsible for rewriting core tenets of the Universal Declaration of Human Rights", adding: "We seem all guilty for 9/11."
Cuba also took exception to Bush's speech where he called for an end to a "cruel dictatorship" and prompted the country's delegation to leave the room.
Felipe Perez Roque, Cuba's foreign minister, described Bush's talk of democracy as a lie, saying he came into office "through fraud and deceit".
"We would have been spared his presence yesterday and would have listened to president Al Gore talking about climate change and the risks to our species," he said.
'Industry of death'
Nuri al-Maliki, the Iraqi prime minister, under pressure to show progress on resolving sectarian violence, sought international help by outlining the concerns and hopes of the Iraqi people.
But his claims that Iraqi forces "with loyalty to country, not sect nor ethnicity" were "ready to assume full responsibility for our security in order to defend the democratic gains" were met with scepticism.
On the same day, the Pentagon told congress it was ready to sell Iraq up to $2.3bn in weapons to help the Iraqi army expand and take over missions now carried out by US and allied forces.
The US defence secretary also asked congress to approve nearly $190bn more in funding for the wars in Iraq and Afghanistan - only $1bn of which was to be spent on training and equipping Iraqi security forces.
Denouncing war in his speech, Evo Morales, the president of Bolivia, accused some countries of perpetrating death by being in the arms race.
"Some countries are in an arms race, I don't understand that. We are talking about social movement; we are talking about a new constitution in Bolivia that renounces war.
"I'm convinced that war is the industry of death, and therefore the arms race is one more industry that goes together with that industry of death."