City officials in San Francisco plan to block local government agencies from buying new Apple Macintosh computers.
The move follows the firm's decision to pull out of a green certification scheme designed to identify which electronic devices pose the least risk to the environment.
San Francisco's chief information officer told the BBC that his decision was in line with a long running policy to opt for equipment listed on the EPEAT (Electronic Product Environmental Assessment Tool) registry.
"San Francisco has reached out to Apple and is hopeful that a solution to this challenge can be found in the future," said Jon Walton.
But a statement from Apple suggested it had no plans to reverse its decision.