"Whether it happens in mid-2024 or in 2025 will depend essentially on the condition and working capacity of the ISS. But it is no secret that we will do it," Yuri Borisov told the Rossiya 24 broadcaster.
The Russian space chief promised an orderly withdrawal that is expected to take "up to two years." He said Russia would not give up its responsibility for the 24-year-old station as it goes through its life cycle, up to its likely demise in the ocean.
Borisov said that Russian modules were older than those of US, Japanese and European space agencies. Safety of Russian cosmonauts should be prioritized, he said, as Russia begins working on a new space station.
"The main modules of the ISS are several times over their capacity limits... The lives of Russians — as well as of American astronauts and other foreign crews — are coming to the fore," he explained.
Russian cosmonauts spent months last year hunting elusive cracks in their module. Borisov said the money spent on its maintenance was needed elsewhere.
"Accumulating technical problems have made us think about the future of the crewed space program, which is the construction of a Russian station," he said, adding that the transit from the ISS to a national station should be seamless.