Washington  - Senator John McCain, the presumptive Republican presidential nominee, said Tuesday that he will look to reduce the size of the US nuclear weapons fleet if he wins the White House.

McCain pledged to pursue negotiations with China and Russia on agreements to cut nuclear stockpiles, but said he would also seek a smaller US force while preserving national security.

"I will seek to reduce the size of our nuclear arsenal to the lowest number possible consistent with our security requirements and global commitments," McCain said at the University of Denver in Colorado.

"Today we deploy thousands of nuclear warheads. It is my hope to move as rapidly as possible to a significantly smaller force," McCain said.

McCain said he would not support any plans to develop an earth- penetrating, bunker-busting nuclear bomb, saying the concept "does not make strategic or political sense."

The Bush administration has pursued the technology, only to have Congress strip the funding.

McCain also said the United States should strengthen international treaties on non-proliferation efforts and work closely with allies to prevent the spread of dangerous nuclear technology.

"We cannot achieve our non-proliferation goals on our own," McCain said. (dpa)