Saudi Arabia's Crown Prince Abdullah has called for the creation of an international counter-terrorism centre to help prevent further attacks.
The Saudi prince says the war against terror will be long and bitter
The country's de facto ruler was speaking at a start of a conference in Riyadh attended by top anti-terrorism officials from 50 nations.
The forum also saw a heated exchange between the Iranian and US delegations on what constitutes terrorism.
And Syrian delegates urged the world to condemn Israel's "state terrorism".
Saudi Crown Prince Abdullah said a global counter-terrorism centre could allow nations around the world to "exchange information instantly" to thwart future attacks.
"Terrorism increases in ferocity and violence the more the noose tightens round its neck, but I trust the final result will be victory, tolerance, love and peace," he said.
Saudi Interior Minister Prince Nayaff went further and said security measures were not enough to deal with terror.
Security has been beefed up in Riyadh
He said all aspects of society had to be involved to fight what he called those with deviant thoughts.
Saudi Arabia has clamped down on militant networks but it has been criticised for not doing enough to tackle extremist ideologies that are widespread in the conservative kingdom, reports the BBC's Kim Ghattas in Riyadh.
The gathering appears mostly symbolic - the way for Saudi Arabia to show that it is committed to fight international terrorism, our correspondent says.
But participants say it is also a good opportunity to draw together counter-terrorism officials who would not usually meet.
Delegates from Syria and Iran - two nations accused by the US of being sponsors of terrorism - disputed what they called inaccurate definitions of terrorism.
They said people fighting for freedom under occupation should be seen differently to those who target innocent civilians.
The participants have been divided into four groups that will look into several themes including money laundering and the origins of terrorism.