[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2008/POLITICS/07/16/obama.speech/art.obama2.ap.jpg caption=" Sen. Barack Obama joins in a roundtable discussion on national security Wednesday at Purdue University."]WEST LAFAYETTE, Indiana (CNN) - Sen. Barack Obama on Wednesday said he wants to rid the world of nuclear weapons and pledged to fight emerging threats posed by biological and cyber-terrorism.
"It's time to send a clear message to the world: America seeks a world with no nuclear weapons," the White House hopeful said.
"As long as nuclear weapons exist, we'll retain a strong deterrent. But we'll make the goal of eliminating all nuclear weapons a central element in our nuclear policy."
The remarks, delivered at Purdue University in Indiana before a roundtable discussion with foreign policy experts, come as the senator from Illinois is preparing for a trip abroad. Obama also is seeking to gain traction on national security issues.