SpaceX CEO Elon Musk announced the freezing of the company’s plans for Mars missions for the time being, in favor of prioritizing a project to build a self-expanding city on the Moon.

Musk explained that the long travel time to Mars and the limited launch windows make the project more complex, compared to the Moon, which can be reached at a faster pace.

He confirmed that Mars remains a strategic objective, with work expected to begin within five to seven years.