Tesla Inc. Chief Executive Officer Elon Musk, responding in a tweet to an open letter by Uber Technologies Inc. board member Arianna Huffington urging him to change the way he works, ruled out taking a different approach.

In an interview with The New York Times last week, Musk said he sacrificed family milestones in the race to meet Tesla production targets. “This past year has been the most difficult and painful year of my career,” he told the newspaper.