"The United Nations is an enemy of Islam and Muslims: it is the one which codified and legitimised the setting up of the state of Israel and its taking over of the Muslims' lands," Zawahiri said.
The UN had also agreed to the presence of outsiders, dubbed "Crusaders" by Zawahiri, in Afghanistan and Iraq and had approved the separation of East Timor from Indonesia.
Yet "it doesn't recognize that [right] for Chechnya, nor for all the Muslim Caucasus, nor for Kashmir, nor for Ceuta and Melilla, nor for Bosnia," he added.
The United Nations "is the one which considers Chechnya an inseparable part of Crusader Russia, and consider Ceuta and Melilla inseparable parts of Crusader Spain," he said, referring to two Spanish enclaves in North Africa claimed by Morocco.
The audio released via the monitoring group the IntelCenter was the first installment in a two-part series to answer about 100 questions put to Zawahiri, known as Al-Qaeda's ideological thinker, via online militant forums.
He grouped his replies into four sections - the killing of innocents, Iran, Egypt and Palestine - and denied that the Al-Qaeda network had been responsible for the loss of innocent Muslim lives.
"We haven't killed the innocents, not in Baghdad, nor in Morocco, nor in Algeria, nor anywhere else," Zawahiri said in the audio lasting one hour and 43 minutes, which marked his third public message this year.