The new group will become "a counter terrorism network that is as nimble and adaptive as our adversaries," US Secretary of State Hillary Clinton said at the inaugural meeting of the Global Counter terrorism Forum, or GCTF.
"Let us pledge to learn as much as we can from one another," she said at the meeting in a New York hotel on the margins of this week's United Nations General Assembly.
The United States and Turkey will be the initial co-chairs of the group's coordinating committee.
Major nations from Africa, Asia, the Middle East and Europe are members of the group, which includes leading Muslim nations like Egypt and Pakistan as well as emerging economic powers like China.
A US State Department official said the GCTF was created after the failures of earlier initiatives that did not include a broad enough array of countries.
The GCTF will initially have five working groups, one focusing on criminal justice and rule of law; one on countering violent extremism; and three aimed at building counter-terrorism capacity in the Sahel, the Horn of Africa and Southeast Asia.
The 30 founding members of the group are Algeria, Australia, Britain, Canada, China, Colombia, Denmark, Egypt, the European Union, France, Germany, India, Indonesia, Italy, Japan, Jordan, Morocco, the Netherlands, New Zealand, Nigeria, Pakistan, Qatar, Russia, Saudi Arabia, South Africa, Spain, Switzerland, Turkey, the United Arab Emirates and the United States.