President Bush on Friday vetoed a 1991 intelligence bill, saying it could have a chilling effect on American diplomacy because it would restrict other countries carrying out covert actions for the United States.

The legislation would have authorized all U.S. intelligence activities in the year that began Oct. 1 and contained provisions aimed at gradually winding down American support for covert conflicts in Afghanistan, Angola and Cambodia.Bush said he was withholding his signature from the measure primarily because it included under a new definition of "covert action" any U.S. request of a foreign government or private citizen to mount a covert action on America's behalf.

In a statement issued late Friday, Bush said the bill would have forbidden U.S. officials from the "expression of certain views" without prior notice to Congress.

Such a legal restriction could "seriously impair the effective conduct of our nation's foreign relations," Bush said. It could "have a chilling effect on the ability of our diplomats to conduct highly sensitive discussions concerning projects that are vital to our national security."

House Intelligence Committee Chairman Anthony C. Beilenson, D-Calif., who got no advance notice of the veto, said in a statement that he was "deeply disappointed" by the move and noted that he had been told the measure was going to be signed.