US President Bill Clinton said Friday he would leave to his successor a decision on whether to deploy a controversial national missile shield that many fear may spark a new arms race.

Clinton said that although some initial tests of parts of the system were “promising,” much more information was needed before he could responsibly make a decision to commit the billions of dollars needed to deploy national missile defense (NMD).

“Though the technology for national missile defense is promising, the system as a whole is not yet proven,” Clinton said in a speech to students at Georgetown University here.

“There is a reasonable chance that all these challenges can be met in time, but I simply cannot conclude, with the information I have today, that we have enough confidence in the technology and the operational effectiveness of the entire NMD system to move forward to deployment.

“Therefore, I have decided not to authorize deployment of a national missile defense at this time,” Clinton said.

He stressed that the decision would not have “a significant impact” on when NMD could be deployed ” if the next president decides to go forward” by 2006 or 2007.

“If the next president decides to move forward next year, the system still could be ready in the same time frame,” he said.

In addition to the technological issues, the president said concerns expressed by Washington’s NATO allies about the system, and vehement objections from Russia and China played a role in his decision not to proceed with deployment, but stressed that “no nation can ever have a veto over American security.”

Russia has warned the proposed system would abrogate the 1972 Anti-Ballistic Missile (ABM) treaty and seriously tip the balance of power, and China has hinted that its concerns about the shield could prompt an expansion of its nuclear arsenal.

“It would be for better to move forward in the context of the ABM and allied support,” he said, adding, however, that that had not yet been achieved.