The United States said on July 26 that Russia has not formally notified NASA of its intention to quit the International Space Station (ISS) but that it is already "exploring options" for dealing with a withdrawal.
The newly appointed head of Roskosmos, Yuri Borisov, said Russia will quit the ISS after 2024 to focus on building its own project in outer space.
Moscow's move to abandon one of the last areas of cooperation between the United States and Russia comes at a time of heightened tensions between the Kremlin and the West over the Moscow's invasion of Ukraine.
Speaking at a meeting with Russian President Vladimir Putin on July 26, Borisov said Moscow will fulfill all of its obligations at the ISS before leaving.
“The decision to leave the station after 2024 has been made,” Borisov said.
White House spokeswoman Karine Jean-Pierre said Russia has not formally notified the United States of its intention to withdraw from the ISS, but said the United States is "exploring options to mitigate the potential impacts on the ISS beyond 2024 if Russia does withdraw."
NASA had no official response.
U.S. State Department spokesman Ned Price called Borisov's announcement “an unfortunate development” given the “valuable professional collaboration our space agencies have had over the years.”
Borisov's statement came a week after NASA, the U.S. space agency, and its Russian counterpart, Roskosmos, agreed on exchange flights to the ISS on Elon Musk's SpaceX rockets for cosmonauts, while U.S. astronauts will be able to fly on Russia's Soyuz.
"We will continue the piloted program in compliance with the plans already approved," Borisov said.
"The main focus going forward will be on creating a Russian orbital station," he added, noting Roskosmos would also make scientific space research a priority.
Putin appointed Borisov to replace sacked Roskosmos chief Dmitry Rogozin on July 15. Rogozin had previously said that Russia could not agree to extend his country's role on the ISS beyond 2024 unless the United States lifted sanctions on two Russian companies that had been blacklisted for their suspected military ties.
NASA has previously called Russian participation crucial to keeping the space station running. The ISS is due to be retired after 2024, but NASA says it can remain operational until 2030 and would like the partnership with Russia to continue through then.
The ISS was launched in 1998 at a time of hope for cooperation in space between the United States and Russia. It is jointly run by Russia, the United States, Europe, Japan, and Canada, and has been continuously inhabited by astronauts and cosmonauts from those countries and others for nearly 22 years.