The Republican Party sent a letter to the Secret Service on Friday urging the police agency to keep protesters farther away from the venue for the Republican National Convention in Milwaukee in July.

The three-page letter, signed by Todd R. Steggerda, counsel to the Republican National Committee, objected to the placement of an area where protesters would be allowed to demonstrate. Mr. Steggerda argued that convention attendees would be forced to pass by the protesters on their way into the venue, raising the potential for confrontations.