Speaking at the opening of the annual UN General Assembly summit in New York on Tuesday, Ban said "I appeal to all states to stop fuelling the bloodshed and to end the arms flows to all parties".
The UN chief also called on Syrian President Bashar al-Assad and the opposition - and "all those in this hall with influence over them" - to work immediately to arrange a second Geneva conference aimed at reaching a political solution to the crisis that has wracked Syria for more than two years.
"Military victory is an illusion. The only answer is a political settlement," he said.
Ban said the response to last month's "heinous use of chemical weapons" outside Damascus "has created diplomatic momentum - the first signs of unity in far too long".
Concerns were highly on the rise in the region following US threats to bomb the country over conflicting reports of a chemical attack which Washington rushed to blame on the Syrian government.
US military plans were canceled with Russia’s mediation that sought to ease the tensions by putting Syria’s stockpile of chemical weapons under international control.
The offer was widely welcomed both in Syria and other countries that were concerned by US military ambitions and its regional consequences.
Syria and Russia have provided the United Nations with evidence showing that the August 21 chemical attack was a false-flag operation led by anti-Syria militants to open the way for direct US military involvement.
The US has been giving military support to anti-Syria militants through CIA operatives near Syria borders, but the White House had threatened that it would enter the war if a chemical attack was carried out by the Syrian army.
Washington has remained silent on whether it would intervene to help Syrian people and army if the militants were responsible for the attack.
SHI/SHI