Ki-moon has issued an unusually stern denouncement of security council inaction over Syria, which he called "a regional calamity with global ramifications".
"This is a serious and growing threat to international peace and security which requires security council action," Ban said. "The international community should not look the other way as violence spirals out of control."
UN officials said Ban had become increasingly frustrated by the security council's deadlock over Syria and had decided to speak out in the bluntest terms.
He also called for those responsibility for atrocities in Syria to be held accountable, noting "there is no statute of limitations for such extreme violence", and placing most of the blame on the Assad regime.
At present, Russian and Chinese objections are blocking the International Criminal Court from launching an investigation into war crimes.
"Brutal human rights abuses continue to be committed, mainly by the government, but also by opposition groups. Such crimes must not go unpunished," he said.
"It is the duty of our generation to put an end to impunity for international crimes, in Syria and elsewhere. It is our duty to give tangible meaning to the responsibility to protect."
The responsibility to protect was a principle adopted by the UN in the 1990s, stating that the international community had to intervene to protect civilian populations when their states were unwilling or unable to do so.
Ban also had pointed words for two leaders due to speak at the same UN podium later in the week, Binyamin Netanyahu and Mahmoud Ahmadinejad, calling on them to pull back from the brink of a new Middle East conflict, and to ratchet down their rhetoric.
"I … reject both the language of delegitimisation and threats of potential military action by one state against another. Any such attacks would be devastating. The shrill war talk of recent weeks has been alarming," Ban said. "Leaders have a responsibility to use their voices to lower tensions instead of raising the temperature and volatility of the moment."
Netanyahu has been successful in displacing the Israel-Palestinian impasse from the international agenda by repeated threats to take military action against Iran. But the secretary-general warned that his government's policies in the West Bank were stoking renewed conflict.
"The two-state solution is the only sustainable option. Yet the door may be closing, for good. The continued growth of Israeli settlements in the occupied Palestinian territory seriously undermines efforts toward peace. We must break this dangerous impasse," Ban said. – © Guardian News and Media 2012