Jesse L. Jackson and some of the other presidential candidates cannot visit U.S. forces in the Persian Gulf unless such visits are part of official duties, Defense Secretary Caspar W. Weinberger has decided.

Jackson, a candidate for the 1988 Democratic presidential nomination, had asked the Pentagon to let him visit U.S. forces in the gulf region.

Defense Department spokesman Bill Caldwell said Weinberger denied the civil rights leader's request in a letter dated Nov. 10.

In Chicago, Jackson's campaign office said it had received no Pentagon rejection, only a letter from the State Department saying that U.S. embassies in the region would help plan his schedule.

The Pentagon policy was issued because of "requests from presidential candidates to conduct well-publicized visits to U.S. military forces on duty in the Persian Gulf" and congressional requests for the Defense Department to clarify its visitation policy, the statement said.

Candidates who are members of Congress -- and Vice President Bush, a candidate for the GOP presidential nomination -- would appear to be favored by the new policy.

The statement said requests for visits to the gulf by members of Congress would be reviewed on "a case-by-case" basis, subject to a recommendation by the Pentagon's legislative group.